GIFT  OF 
Miss  E.M.   Boulton 


LOCKED 
CASE 


, 

•fi 
/ 

, 


THE 


POCKET  ANATOMIST: 


A  COMPLETE  DESCRIPTION  OF  THE  ANATOMY 
OF  THE  HUMAN  BODY, 


THE  USE  OF   STUDENTS, 


M.  W.  HILLES, 

FORMERLY  LECTURER   ON  ANATOMY  AND  PHYSIOLOGY  AT  THE 
WESTMINSTER  HOSPITAL  SCHOOL  OF   MEDICINE,   ETC. 


SECOND    EDITION. 

PHILADELPHIA: 
LINDSAY   AND   BLAKISTON. 

1867. 


BIC 

IHO 


PKEFACE. 


To  the  student  preparing  for  his  examination  at  the 
several  Medical  Colleges,  works  which  contain  a  con- 
densed description  of  the  structures  and  functions  of  the 
human  body  are  essentially  useful,  as  they  not  only  con- 
vey concise  information  on  these  subjects,  but  they  also 
direct  his  attention  to  the  most  important  points  connec- 
ted therewith.  Such  works  are  not  intended  to  supersede 
the  more  elaborate  treatises  on  the  various  branches  of 
medical  science :  these  must  be  studied  also,  as,  without 
their  aid,  it  is  vain  to  suppose,  that  sufficient  information 
can  be  obtained  to  enable  the  student  to  enter  upon  the 
pursuit  of  the  profession  which  he  has  selected,  with 
credit  to  himself,  or  with  advantage  to  those  who  may 
intrust  their  health  and  lives  to  his  care. 

There  is  no  "short  road  to  knowledge:"  the  foundation 
must  be  first  carefully  laid,  by  close  study  and  diligent 
research;  when  this  has  been  accomplished,  the  attention 
will  be  profitably  directed  to  the  arrangement,  classifica- 
tion, and  condensation  of  the  knowledge  thus  obtained; 
knowledge  is  not  a  burden,  nor  is  it  unprofitable:  it  is 
only  in  the  pursuits  of  after  life  that  we  feel  the  truth  of 
this,  and  begin  to  experience  the  advantage  of  having 
laid  up,  in  our  earlier  years,  a  store  of  information  upon 
which  we  may  draw  fearlessly  on  occasions  of  difficulty. 

970070 


Anatomy  may  be  said  to  be  the  basis  on  which  all 
medical  science  rests;  without  correct  and  extensive 
anatomical  knowledge  the  practice  of  surgery  must  be 
fraught  with  danger,  and  that  of  medicine  empirical  and 
of  doubtful  advantage.  The  medical  bodies  of  the  United 
Kingdom  happily  insist  on  all  candidates  for  their  de- 
grees or  diplomas  possessing  a  competent  knowledge  of 
anatomy;  it  is  much  to  be  regretted  that  a  deficient 
supply  of  subjects  should  still  exist,  and  present  serious 
obstacles  to  the  attainment  of  that  practical  information 
which  is  so  desirable. 

This  work  is  based  on  a  treatise  favourably  known  to 
the  profession  as  Savage's  Anatomist,  and  written  by  my 
friend  and  former  colleague,  Mr.  Henry  Savage.  It  now 
appears,  from  its  enlarged  and  altered  form,  rather  as  a 
new  work  than  a  new  edition  of  a  former  treatise.  I 
trust  that  in  this  form  it  will  continue  to  meet  with 
approval  and  support. 


CONTENTS. 


CHAPTER  I. 


THE  HEAD 13 

Cranium 13 

Occipito  frontalis 13 

Muscles  of  External  Ear 14 

Face 14 

Muscles  of  ditto 14 

"  nose 16 

"  lower  jaw 16 

Vessels  and  nerves  of  face 16 

Parotid  gland 17 

CHAPTER  II. 

THE  NECK 19 

Muscles  of  ditto 19 

"         between  lower  jaw  and  os  hyoides 20 

"         oftongue '      20 

"         between  os  hyoides  and  sternum 21  * 

Thyroid  gland 22 

Triangles  of  neck 23 

Submaxillary  gland 24 

Sublingual    ditto 24 

Vessels  and  nerves  of  neck 25 

Deep  muscles 25 

Larynx 26 

Thyroid  cartilage 27 

Cricoid        "        27 

Arytsenoid  "        27 


VI  CONTENTS. 

THE  NECK 

Epiglottis 

Epiglottic  gland 

Muscles  of  larynx 

Pharynx 

Muscles  of  ditto 

Arteries  and  nerves 

Velum 

Tonsil..., 


CHAPTER  III. 

THE  UPPER  EXTREMITIES 35 

Muscles  of  anterior  and  lateral  parts  of  trunk...  35 

Muscles  on  posterior  part  of  trunk 37 

Superior  extremity 41 

Muscles  of  shoulder 41 

"         of  arm 43 

Arteries  of  shoulder 44 

Nerves  of  ditto 45 

Axilla 45 

Mammary  gland 45 

Fore  arm 46 

Muscles  of  ditto 47 

Vessels  and  nerves  of  ditto 50 

Hand 51 

Muscles  of  ditto 52 

Vessels  and  nerves  of  ditto 54 


CHAPTER  IV. 

THE  TRUNK 55 

Thorax 55 

Pleura 56 

Anterior  Mediastinum 56 

Thymus  gland 57 

Lungs 57 

Bronchial  tubes 58 

Vessels  and  nerves  of  lungs 58 

Trachea 59 

Posterior  Mediastinum 60 


CONTENTS.  Vll 

THE  TRUNK.  PA«E 

(Esophagus 60 

Vena  azygos 60 

Thoracic  duct 61 

Abdomen 62 

Muscles  of  abdomen 62 

Diaphragm 65 

Viscera  of  abdomen 67 

Peritoneum 67 

Stomach 69 

Small  intestines 71 

Large  ditto 72 

Liver 74 

Gall  bladder 76 

Pancreas .'. 77 

Spleen 77 

Hernia 78 

Inguinal  ditto 78 

Femoral  ditto 92 

Urinary  organs 100 

Kidneys 100 

Ureters 101 

Suprarenal  capsules 101 

Bladder 102 

Urethra 103 

Male  organs  of  generation 104 

Scrotum 104 

Testes 104 

Spermatic  cord 106 

Vesiculse  seminales 106 

Prostrate  gland "  106 

Penis , 107 

Perineum 108 

Muscles  of 108 

Female  organs  of  generation Ill 

Uterus 112 

Ovaries 113 

CHAPTER  V. 

THE  INFERIOR  OR  LOWER  EXTREMITIES 114 

Muscles  of. 114 


Vlll  CONTENTS. 

THE  INFERIOR  OR  LOWER  EXTREMITIES.  PAGE 

Muscles  of  hip  joint 114 

'•'           front  and  sides  of  thigh 117 

"           posterior  part  of  thigh 119 

Vessels  and  nerves  of  thigh 120 

Leg 121 

Muscles  of. 121 

Foot 124 

Muscles  of. 124 

Vessels  and  nerves  of  leg  and  foot 127 


CHAPTER  VI. 

FASCIJE 129 

Cervical 130 

Abdominal 330 

Pelvic 132 

Perineal 132 

Lata 133 

Crural 135 

Plantar 136 

Brachial 137 

Palmar 138 

CHAPTER  VII. 

VASCULAR  SYSTEM 139 

Heart 139 

"     structure  of. 142 

"     development  of. 143 

"     investments  of. 143 

Arteries 145 

pulmonary ^  145 

aorta 145 

innominata 147 

carotid 147 

"         right  common 147 

"         left  common 147 

"         External 148 

anterior  branches 148 


CONTENTS.  IX 

VASCULAR  SYSTEM.  PAGE 

Arteries  posterior 149 

inner 149 

terminal 149 

internal 150 

branches 150 

Cerebral  branches    from  Basilar 151 

Subclavian 152 

right ;. 152 

"         left 152 

branches 153 

Axillary 154 

branches 154 

Brachial 155 

branches 155 

Radial 156 

branches 156 

Ulnar 157 

branches 157 

Aorta 

Thoracic 158 

Abdominal 159 

Coaliac  axis 159 

Hepatic 160 

Splenic 160 

Sup.  Mesenteric 160 

Inf.  Mesenteric 161 

Renal 161 

Spermatic 162 

Terminal  branches '   162 

Iliacas  Communes 162 

"       internal 163 

branches 163 

Gluteal 164 

Ischiatic 164 

Int.  Pudic 165 

"         External 166 

branches 166 

Femoral 166 

branches 167 

Profunda....                               167 


X  CONTEXTS. 

VASCULAR  SYSTEM —  PAGE 
AORTA — 

Popliteal 168 

branches 168 

Tibial  anterior 168 

"       posterior 169 

branches 169 

Collateral  circulation 170 

Venou.-  Sysrom 172 

Vein,  Internal  Jugular 172 

"     Labial 172 

"     Ext.  Jugular 172 

"    Axillary 172 

Vena  Innom.,  right 173 

left 173 

Vena  cava,  superior 173 

"     Vein,  int.  saphena 173 

'*'     ext.    saphena 173 

"     popliteal K3 

"     common  iliac 173 

Vena  cava  inferior 174 

"     porta 174 

Lymphatic  system 174 

Thoracic  duct 174 

CHAPTER  VIII.J 

THE  NERVOUS  SYSTEM 1^6 

Spinal  cord 176 

Medula  oblongata 179 

Corpus  olivaria 

"         restiformia 

Filamenta  arciformia 

Pons  Varolii 181 

Crura  cerebri 

Cerebellum 

Cerebrum 

Tuber  cinereum 

Fissure  of  Sylvius 

Corpus  callosum 

"         striatum  189 


CONTENTS.  XI 

THE  NERVOUS  SYSTEM.  PAGE 

Third  Ventricle 190 

Membranes  of  brain 191 

Dura  mater 192 

Sinuses 192 

Arachnoid r/r 194 

Pia  mater 194 

Structure  of  the  brain 194 

Vessels 199 

Spinal  nerves 200 

Cervical  plexus 203 

Brachial 204 

Intercostal  nerves 206 

Lumbar  plexus 207 

Sacral 209 

Cerebral  nerves 211 

Sympathetic   system 214 

Cerebral  ganglia 216 

Semilunar  ganglion 216 

CHAPTER  IX. 

BONES,  LIGAMENTS,  AND  JOINTS 218 

Bones  of  the  head 218 

frontal 218 

parietal 219 

occipital 220 

temporal 221 

sphenoid 223 

ethmoid ; 224 

of  face 225 

Inferior  maxilla 2-8 

Temporo-maxillary  articulation 229 

Spine ! 230 

"     ligaments 231 

Ribs 232 

Sternum 233 

Ligaments  of  ribs 234 

Bones  of  upper  extremity..,. 234 

Shoulder  joint 237 

Bones  of  fore-arm 237 


Xll  CONTENTS. 

BONES  OF  THE  HEAD  PAGE 

Elbow-joint 238 

Carpus 239 

Wrist-joint 240 

Bones  of  inferior  extremity 241 

pelvis 241 

"  articulations  of 244 

feinur 245 

Hip-joint 246 

Knee-joint 248 

Ankle-joint 252 

CHAPTER  X. 

ORGANS  OF  SENSE 254 

Eye 254 

Nose...: 259 

Ear 260 

Tongue 262 

Skin...,                                                  263 


THE   ANATOMIST. 


The  he'Jid;  .n'ecK,  trb'hk/a^<},extH;rmta©s  form  the 
principal  divisions 'of  the  lluman-i>bdy/:>  •> 


CHAPTER  I. 

THE    HEAD 

Consists  of  the  Cranium  and  Face. 
SECTION  I. 

The  Cranium  is  covered  by  the  scalp,  composed  of 
— 1.  The  Skin.  2.  The  occipito-frontalis  muscle. 
3.  The  periosteum. 

The  skin  of  the  scalp  is  dense  and  firm,  and  is  fur- 
nished with  hair  and  sebaceous  follicles  and  granu- 
lated fat. 

Occipito-frontalis  is  bicipital,  with  a  central  tendon 
or  aponeurosis,  Or.  two  ext.  thirds  of  the  super,  trans- 
verse occipital  ridge,  and  adjoining  part  of  the  mas- 
toid  process;  Ins.  nasal  bones,  int.  angular  process,  the 
rest  of  its  fibres  intermixing  with  the  corrugator  sur 
percilii,  and  orbicularis  palp.  Covers  the  whole  skull, 
excepting  the  temporal  fossae.  Use,  to  raise  the  skin 
of  the  forehead,  eyebrows,  and  eyelid.  The  scalp  is 
supplied  with  blood  from  the  frontal  arteries  in  front 
the  temporal  and  aural  on  the  sides,  and  the  occipital1 
posteriorly ;  its  nerves  are  derived  from  the  fifth,  por- 
tio  dura,  ascending  cervical,  and  first  cervical 
branches;  it  is  loosely  connected  to  the  periosteum 
2  1 


14  THE    FACE. 

and  bone  by  areolar  tissue,  and  thus  moves  freely  on 
the  skull.     On  the  side  of  the  head  are 

The  Muscles  of  the  External  Ear,  3. 

Superior  auris,  or  attollens  aurem,  Or.  from  the  cra- 
nialaponeurosis  on  the  side  of  the  cranium,  immedi- 
ately above  the  ex't.  ear;  Ins  t'K>  upper  and  anterior 
part  of  the  cartilage  of  ths  eir. 

Anterior  auris,  or  attrahens  aurem,  Or-  posterior  part 
of  zygomati/j  projjo&s, and. cranial rat>6neurosis;  Ins. 
front  part'uf  h  -li::. 

Posterior  auris,  or  retrahens  aurum,  Or.  from  the 
the  mastoid  process  above  sterno-mastoid;  Ins.  back 
part  of  concha.  The  use  of  these  muscles  is  indica- 
ted by  their  names. 

SECTION  II. 
The  Face 

is  covered  by  a  delicate  vascular  skin,  closely  con- 
nected with  the  subjacent 

Muscles,  33. 

Orbicularis palpebrarum,  Or.  the  upper  edge  of  the 
tendo  oculi,  and  int.  ang.  process;  Ins.  the  lower  edge 
of  the  tendon,  ascending  process  of  the  maxilla  sup., 
and  inner  third  of  the  lower  edge  of  the  orbit.  The 
tendon  crosses  the  junction  of  the  lower  two-thirds 
with  the  upper  third  of  the  lacrymal  sac.  Use,  to 
close  theeyelids,  by  depressingtheupper,  tocompress 
the  lacrymal  sac,  and  force  the  tears  into  the  nasal 
duct. 

Corru gator  super cilii,  Or.  inner  end  of  the  super- 
ciliary ridge ;  Ins  orbic.  palpebr.  at  its  middle.  The. 
following  four  m.  arise  in  succession  from  the  inner 
canth. 

Levator  labii  super,  alseque  nasi,  Or.  narrow  from 
the  inner  angular  process  beneath  the  tendo  palpe- 


MUSCLES    OF    FACE.  15 

bra?:  Ins.  skin  of  the  ala  nasiand  upper  lip.  and  into 
the  orbic.  oris  muscle. 

Lcvator  labti proprius,  Or.  broad,  inner  half  of  the 
edge  of  the  orbit :  Ins.  skin  and  hair  bulbs  of  the  upper 
lip;  supposed  to  render  the  hair  erect, as  in  the  feline 
tribes. 

Zi/ffomaticui?  m-ir,^r  Q;.,  narrow  i>otu  ihe  inf.  edge 
of  the  os  mala;  '  .umled  wit^i  those  of  the 

above  mus-cle.   , 

Zygomct*iciiss(  road  u-oai  a  groove  on  the 

OS  mala,  a  trove  its  lo\\i.v  euge;  i:u\  iiavyuv  into  the 
labial  commissure. 

Lcvator  anyuli  oris  (Caninus,)  Or.  broad  from  the 
canine  fossa://?*,  narrow  with  the  zyg.  maj.  into  the 
labial  commissure;  the  infra  orbitar  nerve  and  artery 
appear  between  this  and  the  levat.  prop.  m. 

Depressor  anyuli  oris.  Or.  broad  from  the  ext.  ob- 
liqueline  of  infer,  maxilla  ;'//<<«.  narrow  with  the  zyg. 
major  and  eaninus  m.  into  the  labial  commissure. 
Its  fibres  are  partly  confounded  with  those  of  the  pla- 
tysma. 

Depressor  labii  inf., Or.  broad  from  the  same  line 
as,  but  internal  to,  the  last  m. ;  Ins.  broad  into  the 
skin  of  the  lower  lip.:  united  with  its  fellow  above, 
but  separated  below  by  the 

Lcrator  labii  inf.  vclmenti,  conical,  Or.  from  a  fossa 
close^othesymphysis  menti;  Ins.  by  diverging  fibres 
into  the  skin  ami  hair  bulbs  of  the  skin.  Th« 
of  the  preceding  muscles  is  indicated  by  their  names, 
the  zygomatici  draw  the  angle  of  the  mouth  upwards 
and  backwards. 

Ituccinator  Or.  1,  super,  alveola1,  from  that  of  the 
first .iuolar  tooth  to  the  last ;  "2.  corresponding  alveola* 
of  the  lower  jaw;  ;>,  ptergo  maxillary  ligament; 
Ins.  the  labial  commissure,  its  lower  fibres  crossing 
the  upper.  These  muscles  are  antagonized  by  the 
succeeding.  /V,  to  press  the  cheek  against  the  teeth, 
so  aa  10  preVvMit  the  food  passing  between  them. 


16  MUSCLES  OF  THE  LOWER  JAW. 

to  assist  in  mastication,  articulation,  blowing,  and 
sucking. 

Orbicularis  oris.  This  sphinctic  muscle  is  composed 
of  two  portions,  corresponding  to  the  upper  and  lower 
lips.  Their  fibres  decussate  at  the  labial  commissure 
to  become  continuous,  the  upper  -portion  with  the 
lower  fibres  ro'i,tke  bucciriatOtf,  3,ntl;mdy  versa.  Use, 
to  close  and  corrugate  th&inc':. 

•t  Mkw^-f.f  &t  irv.se,  ' 


Pyramid'alds  ndsi.  •'  A  few  fibres  of  th'e  frontalis  m., 
descending  on  each  side  of,  and  parallel  to,  the  nasal 
suture  to  be  lost  in  the  compressor  nasi. 

Compressor  nasi,  Or.  narrow  from  the  edge  of  the 
canine  fossa;  the  two  m.  expand  so  asHo  cover  the 
nasal  cartilage  and  some  part  of  thealse,  and  unite  by 
means  of  a  thin  fascia  on  the  dorsum  nasi. 

Depressor  alse  nasi,  Or.  narrow  close  to  the  median 
line  from  a  fossa  on  the  alveola  of  the  incisor  tooth  ; 
Ins.  by  diverging  fibres  into  the  the  orbic.  oris,  alee 
nasi,  and  septum. 

Naso  labialis,  (Albinus,)  from  the  under  part  of  the 
septum  nasi  runs  downwards  and  backwards,  and  is 
lost  in  the  orbic.  oris. 

Muscles  acting  on  the  Lower  Jaw. 
To  shut  it,  2. 

Masseter,  Or.  1,  by  a  strong  fascia  from  the  ant. 
two-thirds  of  the  edge  of  the  zygoma,  and  adjoining 
portion  of  the  super,  maxilla;  2,  by  a  thinner  fascia 
from  the  post,  third  of  the  zygoma;  3,  from  the  inner 
surface  of  the  zygoma.  Ins.  the  first  portion,  angle 
of  the  jaw;  the  second,  ext.  surface  of  the  ramus; 
and  third,  ext.  surface  of  the  coronoid  process. 

Temporalis,  Or.  I,  Temporal  fossa;  2.  Temporal 
aponeurosis.  Ins.  by  a  strong  narrow  tendon  into  the 
coronoid  process  of  the  inf.  maxilla,  and  sometimes  by 


VESSELS  AND  NERVES  OF  THE  FACE.       17 

an  additional  fasciculus  and  tendon  into  the  inner 
edge  of  the  ramus.  The  horizontal  motion  of  the 
lower  jaw  is  effected  by  2  m. 

Pterygoideus  ext.,  Or.  1,  the  whole  outer  surface  of 
the  ext.  pterygoid  plate  and  adjoining  portion  of  the 
tuberosity  of  the  palate  bone:  2,  from  a  ridge  on  the 
temporal  bone,  which  separates  the  temporal  from  the 
zygomatic  fossa.  Ins.  fossa  on  the  anterior  surface  of 
the  neck  of  the  condyle  of  the  lower  jaw  and  edge  of 
the  interarticular  cartilage;  the  int.  max.  art.  enters 
the  pterygoid  fossa  between  its  two  origins. 

Pterygoideus  ext.,  Or.  1,  fossa  between  the  ptery- 
goid plates;  2,  the  hamular  process;  3,  tuberosity 
of  the  palate  bone ;  it  passes  downwards,  backwards, 
and  outwards,  to  be  ins.  into  the  inner  surface  of  the 
angle  of  the  lower  jaw.  The  interval  between  the 
muscles  below  is  traversed  by  the  int.  maxil.  art.  and 
vein,  ^and  the  dental  and  gustatory  nerves.  The 
dental  nerve  and  artery,  in  their  descent,  separate 
the  latter  muscle  from  the  ramus  of  the  jaw.  The 
lateral  or  grinding  motion  of  the  lower  jaw  is  effect- 
ed' chiefly  by  the  pterygoid  muscles,  and  in  this  the 
muscles  of  either  side  act  alternately,  and  not  con- 
jointly, as  is  the  case  in  most  other  muscles.  These 
last  four  muscles,  although  usually  included  amongst 
those  of  the  face,  do  not  strictly  belong  to  this  part. 

In  the  dissection  of  the  face,  numerous  vessels  and 
nerves  are  found  supplying  the  skin,  muscles,  &c.  The 
principal  arteries  are  derived  from  the  labial  branch 
of  the  ext.  carotid,  the  frontal  branch  of  the  ophthal- 
mic, the  infra  orbital,  and  the  inferior  dental 
branches  of  the  internal  maxillary  artery;  the  nerves 
are  the  frontal,  infra  orbital,  and  inferior  maxillary, 
or  dental  of  the  5th,  branches  of  the  portio  dura  and 
of  the  cervical  plexus.  The  masticatory  actions  of 
the  masseter,  temporal,  pterygoid,  and  buccinator 
are  supplied  by  the  non  ganglionic  portion  of  the  3d 
division  of  the  5th. 

*9 


18  THE  PAROTID    GLAND. 


The  Parotid  Gland 

is  met  with  in  dissecting  the  deep  muscles  of  the  face. 
There  are  three  salivary  glands  on  each  side :  1  pa- 
rotid ;  2  submaxillary;  3  sublingual.  Of  these,  the 
parotid  is  the  largest;  it  is  lodged  in  a  quadrilateral 
fossa  behind  the  rainus  of  the  lower  jaw,  which 
bounds  it  in  front;  behind,  is  the  mastoid  process; 
above  the  zygomatic  arch;  and  below,  the  stylo- 
maxillary  ligament.  Its  superficial  surface  is  cov- 
ered by  the  skin,  a  few  fibres  of  the  platysma,  and  a 
continuation  of  the  cervical  fascia;  its  deep  surface 
passes  in  between  the  pterygoid  muscles,  and  is  in 
close  contact  with  the  int.  carotid  artery,  int.  jugular 
vein,  3rd  division  of  the  fifth  nerve,  the  8th  and  9th 
cerebral  nerves,  and  the  styloid  process;  in  its  sub- 
stance are  found  the  portio  dura,  or  pes  anserinus, 
the  ext.  jugular  vein,  and  the  ext.  carotid  artery, 
and  its  terminating  branches.  This  belongs  to  the 
Conglomerate  class  of  glands ;  it  is  granular  in  struc- 
ture, the  granules  being  separated  by  prolongations 
of  the  cervical  fascia;  a  portion  prolonged  on  the 
masseter  muscle  is  called  the  soda  parotidis.  Its 
duct,  Steno's  duct,  arises  from  the  granules  by  small 
radicles,  which  unite  and  form  the  trunk;  this 
crosses  the  masseter  muscle  from  the  anterior  edge 
of  the  gland,  perforates  the  buccinator,  and  opens 
into  the  mouth  opposite  the  second  molar  tooth  of 
the  upper  jaw.  A  line  drawn  from  the  lobe  of  the 
ear  to  nearly  between  the  ala  nasi  and  angle  of  the 
mouth  indicates  its  course.  The  structure  of  this 
duct  is  fibro-mucous;  the  fibrous  or  ext.  coat  is  re- 
markably strong,  the  canal  is  small,  particularly  at 
its  orifice  in  the  mouth.  The  gland  is  supplied  with 
blood  from  the  ext.  carotid  branches,  its  nerves  are 
derived  from  the  cervical  plexus,  the  portio  dura, 
fifth,  and  sympathetic. 


19 


CHAPTER  II. 


includes  the  space  between  the  lower  jaw  above,  the 
clavicles  'beneath,  and  the  cervical  vertebrae  poste- 
riorly ;  it  comprises  the  neck,  properly  so  called, 
the  mouth,  pharynx  and  larynx,  with  numerous 
vessels  and  nerves. 

The  integuments  of  the  neck  are  thin;  beneath 
them  may  be  noticed  the  projections  of  the  principal 
muscles — the  larynx  on  the  mesial  line,  and  the  ext. 
jugular  vein  laterally. 

SECTION  I. 
Muscles  of  the  Neck. 

Platysma  myoides. — Commences  in  the  subcuta- 
neous tissue  over  the  pectoralis  major  and  deltoid; 
Ins.  into  the  fascia  covering  the  parotid  and  masseter 
m.,  the  labial  commissure,  and  ext.  oblique  line  of 
the  lower  jaw;  some  fibres  are  mixed  with  those  of 
the  depr.  angul.  oris,  quadratus  menti,  and  fellow. 
Use,  to  depress  the  angle  of  the  mouth  and  lower 
jaw,  and  to  corrugate  the  skin  of  the  neck. 

Sterno-cleido-mastoideus,  Or.  fleshy  from  the  sternal 
third  or  more  of  the  clavicle,  and  by  a  round  tendon, 
from  the  adjoining  surface  of  the  first  bone  of  the 
sternum ;  Ins.  mastoid  process  and  sup.  transverse 
ridge  of  the  occipital  bone  as  far  as  the  trapezius. 
Traversed  by  the  spinal  accessory  nerve;  the  ext. 
jugular  vein  descends  some  way  upon  it ;  its  ant. 
edge  is  a  guide  to  the  common  carotid  artery.  Use, 
if  both  muscles  act,  the  interior  portion  will  depress 
the  head  anteriorly,  the  posterior  fibres  posteriorly; 
the  sternal  portion  of  each  muscle  will  also  rotate 


20  MUSCLES  OF  TONGUE. 

the  head  to  the  opposite  side,  the  clavicular  portion 
will  depress  it  laterally. 

Between  the  Lower  Jaw  and  Os  Hyoides. 
Depressors  of  the  Jaw.  3 

Digastricus,  Or.  post,  belly,  groove  behind  the  mas- 
toid  process;  ant.  belly,  a  small  fossa  close  to  the 
symphysis  menti.  The  two  bellies  are  united  by  a 
round  tendon,  which  is  attached  to  the  upper  edge 
of  the  body  of  the  os  hyoides  by  means  of  a  few  ten- 
dinous fibres.  The  post  belly  passes  through  the 
stylo  hyoid  m. 

Mylo  hyoideus,  Or.  whole  length  of  the  mylo  hyoid 
ridge ;  Ins.  the  whole  length  of  the  body  of  the  os 
hyoides  behind  the  digastric  tendon,  and  to  a  me- 
dian tendinous  line  extending  from  that  bone  to  the 
symphysis  menti.  It  forms  the  floor  of  the  mouth. 

Genio  hyoideus.  Or.  the  infer,  of  the  two  tubercles, 
on  the  inside  of  the  jaw  close  to  the  symphysis ; 
Ins.  narrow,  body  of  the  os  hyoides  close  to  the 
median  line. 

These  three  muscles  being  removed,  the  following 
are  brought  into  view: — 

Of  the  Tongue,  5. 

Genio  hyo-glossus,  Or.  narrow  tendinous,  from  one 
of  the  sup.  tubercles  on  the  inside  of  the  jaw,  close 
to  the  symphysis,  above  the  former  m.,  it  expands 
like  a  fan,  to  be  Ins.  1,  into  the  body  of  the  os  hyo- 
ides; 2,  the  pharynx  between  that  bone  r.nd  the 
stylo-glossus;  3,  with  its  fellow  into  the  under  sur- 
face of  the  tongue  from  the  base  to  the  apex;  the 
hypoglossal  nerve  passes  between  its  pharyngeal  and 
lingual  portions.  Use  to  depress  the  tongue  in  the 
centre;  the  posterior  fibres  will  draw  the  base  of 
the  tongue  forward,  the  anterior  will  retract  the  tip. 

Lingualis,  or  Sublingualis,  similar  fibres  are  seen 
pn  the  dorsurn  of  the  tongue,  is  a  fasciculus  of  fibres 


MUSCLES  OF  NECK.  21 

running  from  base  to  apex,  between  the  above  m. 
and  the  stylo  and  hyo  glossi.  Use,  to  draw  the  tip 
towards  the  base  of  the  tongue,  so  as  to  render  this 
convex  superiorly. 

Hyo  glossus,  Or.  1,  the  body  of  the  os  hyoides, 
near  the  larger  cornu ;  2,  the  whole  length  of  this 
cornu.  Ins.  side  of  the  tongue,  between  the  lingu- 
alis  and  stylo  glossus.  The  lingual  artery  crosses 
beneath  it  a  little  above  the  cornu,  and  the  lingual 
nerve  in  front  of  it,  a  little  above  the  artery.  The 
gustatory  crosses  its  upper  margin.  Use  to  depress 
the  sides  of  the  tongue,  and  render  the  dorsum  con- 
vex. 

Stylo  glossus,  Or.  narrow,  inf.  half  of  the  styloid 
process;  Ins.  side  of  the  tongue,  from  the  palato- 
glossus  to  the  tip ;  a  second  portion  divides  the  fibres 
of  the  hyo  glossus,  to  join  the  transverse  fibres  of 
the  tongue.  Covered  by  the  gustatory  nerve,  and 
sublingual  gland.  Use,  to  draw  the  tongue  back- 
wards, and  to  elevate  the  lip.  The  two  other  styloid 
muscles  elevate  and  dilate  the  pharynx. 

Stylo  hyoideus,  Or.  narrow,  back  part  of  the  styloid 
process,  near  its  apex;  Ins.  body  of  the  os  hyoides, 
near  the  middle,  gives  passage  to  the  post,  belly  of 
the  digastricus.  Use,  to  raise  and  draw  back  the 
os  hyoides  and  tongue. 

Stylo  pharyngeus,  Or.  vaginal  process  and  back 
part  of  the  base  of  the  styloid  process,  passes  be- 
tween the  two  sup.  constrictors,  with  which  its  sup. 
fibres  are  lost;  Ins.  the  edge  of  the  ala  of  the  thy- 
roid cartilage,  and  side  of  the  pharynx.  The  glossa 
pharyngeal  nerve  runs  on  its  outer  side.  Separates 
the  ext.  from  the  int.  carot.  and  int.  jugular  vein. 

Between  the  Os  Hyoides  and  Sternum,  4. 
Sterno  hyoideus,  Or.  post,  surface  of  sternum,  and 
cartilage  of  the  first  rib,  sternal  end  of  clavicle,  and 
capsule  of  the  joint;  Ins.  lower  border  of  the  body 


22  THYROID  BODY. 

of  the  os  hyoides.  Use,  to  depress  os  hyoides, 
larynx,  and  pharynx. 

Thyro  hyoideus,  Or.  oblique  line  on  the  ala  of  the 
thyroid  cartilage;  Ins.  post,  surface  of  the  body  of 
the  os  hyoides,  and  part  of  its  larger  cornu.  Use,  to 
approximate  the  os  hyoides  and  thyroid  cartilage. 

Sterno  thyroides,  Or.  broad,  post,  surface  of  the 
sternum,  below  the  sterno  hyoideus,  and  from  the 
first  costal  cartilage;  Ins.  oblique  line  of  the  ala  of 
the  thyroid  cartilage.  Use,  to  depress  the  larynx. 

Omo  hyoideus,  Or.  superior  edge  of  the  scapula, 
behind  the  notch;  2,  inf.  edge  of  the  os  hyoideus  at 
the  junction  of  its  body  and  cornu.  The  two  por- 
tions are  united,  about  an  inch  and  a  half  above  the 
clavicle,  by  a  flat  tendon,  which  is  fixed  to  the  latter 
bone  by  a  portion  of  the  deep  cervical  fascia.  Use, 
to  draw  the  os  hyoideus  downwards,  and  to  one  side. 
Two  muscles  extend  from  the  sternum  to  the  head. 

Immediately  beneath  the  preceding  muscles,  and 
lying  in  front  of  the  trachea,  and  extending  later- 
ally on  the  sides  of  the  larynx,  is  a  soft,  deep  red- 
dish body,  the  thyroid  gland  or  body.  This  is  cre- 
scentic  in  shape,  the  concavity  upwards,  convex  an- 
teriorly, concave  posteriorly,  and  consists  of  two 
large  lobes,  the  lateral  lobes  on  either  side,  connected 
in  front  of,  and  in  some  rare  cases  behind  the  tra- 
chea, by  a  narrow  isthmus,  the  central  lobe.  This 
body  is  larger  in  the  infant  and  female  subject.  The 
structure  of  this  body  is  cellular,  the  cells  contain- 
ing a  thin  serous  fluid;  it  is  largely  supplied  with 
blood  by  the  inferior  thyroid  from  the  subclavian, 
the  superior  thyroid  from  the  ext.  carotid,  and  fre- 
quently by  a  middle  thyroid  from  the  arch  of  the  aorta. 
Its  use  is  wholly  unknown.  As  is  usual  in  such 
cases  conjecture  has  been  very  busy  on  the  subject. 

The  muscles  of  the  neck,  by  their  varied  directions, 
divide  the  nearly  square  surface  of  this  region  into 
numerous  spaces,  generally  of  a  triangular  shape, 


TRIANGLES   OF    NECK.  23 

which  are  of  much  importance,  as  containing  several 
large  bloodvessels,  nerves,  and  other  structures.  The 
principle  of  these  are — 

1.  The  Great  Anterior  Triangle.     Bounded  above 
by  the  lower  jaw  and  stylo  maxillary  lig.,  which  form 
its  base ;  in  front,  by  the  mesial  line ;  posteriorly,  by 
the  ant.  edge  of  the  sterno  mastoid;  its  apex  is,  infe- 
riorly,  at  the  sterno  clavicular  articulation. 

2.  The  Great  Posterior  Triangle.     Bounded  below 
by  the  clavicle,  which  forms  its  base ;  in  front,  by  the 
post,  edge  of  the  sterno  mastoid;  behind,  by  the  ant. 
edge  of  the  trapezius ;  its  apex  is  superiorly,  where 
these  muscles  approach,  but  do  not  meet.     Each  of 
these  triangles  is  subdivided  by  the  omohyoid  muscle 
into  two  as  follows — 

1.  Anterior   Inferior    Triangle.     Bounded   by  the 
mesial  line  as  far  as  the  os  hyoideus,  in  front,Jwhicli 
forms  its  base;  above  by  the  anter.  belly  of  the  omo 
hyoid;  below,  by  the  ant.  edge  of  the  sternomastoid.; 
its  apex  is  formed  by  the  crossing  of  these  muscles. 
This  space  contains  the  com.  cartid  art.,  internal 
jugular  vein,  and  par  vagum,  with  some  smaller  ner- 
vous filaments. 

2.  Anterior  Superior  Triangle.     This  is  again  sub- 
divided into  two  by  the  digastric  muscle;  vix. — 

1.  Infra  hyoid  space.  Bounded  above  by  the  os 
hyoides  and  digastric  tendon,  which  forms  its  base; 
internally,  by  the  ant.  belly  of  the  omo  hyoid;  ext. 
by  the  ant.  margin  of  the  sterno  mastoid;  its  apex  is 
at  the  decussation  of  these  muscles.  It  contains  the 
same  parts,  and  generally  the  bifurcation  of  the  com. 
carotid  into  its  two  branches,  the  ext.  and  int.  carotids 

Supra  hyoid,  or  digastric  space.  Bounded  above 
by  the  lower  jaw  and  stylo  maxillary  lig.,  which  form 
its  base;  in  front,  by  the  ant.  belly  of  the  digastric; 
behind,  by  its  post,  belly ;  its  apex  is  at  the  tendon  of 
this  muscle,  where  it  is  attached  to  the  os  hyoides. 
This  space  contains  the  sub  maxillary  and  sublingual 


24  SUBMAXILLARY  AND  SUBLINGUAL  GLANDS. 

glands,  and  labial  and  lingual  arteries,  the  gustatory, 
ninth,  and  chorda  tympani  nerves,  and  Whartonian 
duct. 

1.  Posterior  Inferior  Triangle.     Bounded  below  by 
the  clavicle,  which  forms  its  base;  above,  by  the  post, 
belly  of  the  omo  hyoid ;  in  front,  by  the  post,  edge  of 
the  sterno  mastoid ;  its  apex  is  at  the  decussation  of 
these  muscles.     It  contains  the  subclavian  vein,  the 
subclavian  art.  in  its  third  stage,  and  brachial  plexus ; 
and,  more  superficially,  branches  of  the  cervical  plex- 
us ext,  jugular  vein,  and  some  lymphatic  glands. 

2.  Posterior  Inferior   Triangle.     Much   larger,    is 
bounded  behind  by  the  ant.  edge  of  the  trapezius, 
which  forms  its  base ;  above  and  in  front  by  the  post, 
edge  of  the  sterno  mastoid;  beneath,  by  the  post,  belly 
of  the  omo  hyoid;  its  apex  is  at  the  decussation  of 
these  muscles.     It  contains  the  cervical  plexus,  and 
spinal  accessory  nerve,  the  transversaiis  colli  art., 
and  numerous  lymphatic  glands. 

The  subrnaxillary  and  sublingual  glands  met  with 
in  the  digastric  space  form,  with  the  parotid  already 
described,  the  salivary  glands. 

The  submaxillary  gland  is  lodged  in  a  deep  fossa 
beneath  the  lower  jaw;  bounded  above  by  this, bone; 
beneath  and  in  front  by  the  ant.  belly,  of  the  digas,- 
tris;  behind,  by  its  post,  belly.  It  is  covered  by  the 
skin,  platysma,  and  cervical  fascia,  and  rests  on  the 
mylo  hyoid  andhyoglossus  muscles.  It  is  traversed 
by  the  labial  art,  which  supplies  it  with  blood.  The 
structure  of  this  gland  resembles  that  of  the  parotid, 
but  is  less  granular,  as  the  cervical  fascia  does  not 
send  processes  into  its  interior.  Its  duct,  the  Whar- 
tonian dtict,  is  thin  and  delicate,  and  opens  on  the  side 
of  the  f raj  num.  linguae.  A  prolonged  portion  of  this 
gland  winds  round  the  posterior  edge  of  the  mylo 
hyoid  mus.,  and  joins. 

The  Sublingual  gland,  the  smallest  of  the  salivary 
glands,  lies  immediately  beneath  the  mucous  memb. 


DEEP    MUSCLES   OF    NECK.  25 

of  the  mouth,  and  above  the  mylo  hyoid  muse.  It 
opens  into  the  mouth  by  numerous  orifices  beneath 
the  tongue;  some  join  the  Whartonian  duct. 

All  these  parts  are  bound  down,  retained  in  their 
places,  and  more  or  less  protected,  by  a  dense  layer 
of  fibrous  structure,  the  cervical  fascia.'  (See  Fasciae.) 

SECTION  II. 
The  Vessels  and  Nerves  of  the  Neck. 

The  arteries  met  with  in  the  neck  are  the  right  and 
left  common  carotid  arteries,  with  their  branches,  the 
ext.  and  int.  carotids,  and  the  principal  branches  of 
them;  the  right  and  left  subclavian  arteries,  and 
their  principal  branches;  the  veins  are  the  internal 
and  external  jugular,  and  the  subclavian,  with  their 
principal  branches;  the  nerves  are  the  cervical  and 
brachial  plexuses,  with  their  principal  branches;  the 
par  vagum  or  pneumogastric,  the  lingual  or  ninth, 
and  sympathetic,  with  their  numerous  branches. 

SECTION  III.. 
Deep-seated  Muscles  of  the  Neck,  5. 

The  number  of  scaleni  is  variously  stated.  Albi- 
nus  makes  5,  Sabatier  3,  Chaussier  1,  recent  wri- 
ters 2. 

Scalenus  anticus;  Or.  upper  surface  of  the  first  rib 
at  its  middle,  Ins  ant.  transverse  tubercles  of  the 
sixth,  fifth,  fourth,  and  third  cervical  vertebrae.-,  se- 
parates the  subclavian  vein  from  the  artery;  the 
phrenic  nerve  descends  diagonally  across  its  ant. 
surface. 

Scalenus posticus  ;  Or.  by  two  slips,  1,  from  the  first 
rib  between  its  subclavian  depression  and  tubercle; 
2.  upper  edge  of  the  second,  between  its  tubercle  and 
angle  \Ins.  post,  transverse  tubercles  of  the  six  inf. 
cervical  vertebrae-. -The  subclavian  artery  and  bra- 
3 


26  THE   LARYNX. 

cliial  plexus  pass  between  the  two  scaleni.  The  use 
of  the  scaleni  muscles  is  to  elevate  or  fix  the  ribs  to 
which  they  are  attached,  and  to  depress  the  neck 
forwards,  and  to  one  side. 

Longus  colli,  consists  of  three  distincts  orders  of 
fasciculi,  1,  Or.  ant.  transverse  tubercles  of  thejfifth, 
fourth,  and  third  cervical  vertebras ;  Ins.  fore-part  of 
the  atlas;  2,  Or.  from  the  bodies  of  the  first  three 
dorsal  vertebrae  Ins.  ant,  transverse  tubercles  of  the 
third  and  fourth  cervical  vert.,  3.  Or.  the  bodies  of 
the  four  last  cervical,  and  three  sup.  dorsal,  and  in- 
termediate ligaments;  Ins.  front  of  the  axis  and  third 
cervical  vertebrae-,  -supports  the  great  cervical  vessel 
and  nerves.  Use,  to  bend  the  neck  latterlly,  and  to 
rotate  the  atlas  and  head  on  the  second  vertebrae. 

Rectus  capitis  anticus  major ;  Or.  ant.  transverse 
tubercles  of  the  third,  fourth  fifth,  and  sixth  cervical 
vertebras;  Ins.  broad  into  the  basilar  process  just  in 
front  of  the  foramen  magnum.  •.  supports  the  int. 
carot.  artery,  sup.  cerv.  gang. -.separates  the 'ant. 
scaleni  from  the  long.  coli.  Use,  to  bend  the  head 
and  neck  forward. 

Rectus  capitis  ant.  minor,  beneath  the  former  m. 
Extends  from  the  base  of  the  transverse  pr.  of  the  at- 
las up  wards  and  inwards  to  the  basilar  process. -.sup- 
ports the  sup.  cerv.  ganglion.  Use,  to  bend  the 
head  and  neck  forward  and  a  little  on  one  side. 

SECTION  IV. 

The  Larynx 

is  the  superior  extremity  of  the  trachea,  with  which 
it  is  continuous.  It  opens  superiorly  into  the 
mouth,  and  lies  on  the  mesial  line  of  the  neck,  hav- 
ing the  carotid'  arteries,  internal  jugular  vein,  and 
par  vagum  on  each  side,  the  pharynx  behind,  and 
the  sterno-hyoid,  sterno-thyroid,  and  thyro-hyoid, 
muscles  in  front. 


THE  LARYNX.  27 

The  larynx  is  composed  of  cartilages,  fibre-carti- 
lage, muscles,  mucous  membrane,  and  glands.  Four 
cartilages,  thyroid,  cricoid,  and  two  arytsenoid;  one 
fibro-cartilage,  the  epiglottis;  fourteen  muscles,  the 
thyro-hyoid,  crico-thyroid,  thyro-arytaenoid,  crico- 
arytsenoid  lateralis,  crico-arytsenoid  posticus,  aryte- 
no-epiglottic,  inter,  arytoenoid,  and  thyro-epiglottic. 
The  last  two  are  single  muscles.  One  gland,  the 
epiglottic.  The  mucous  membrane  lines  the  interior 
of  the  larynx. 

The  thyroid  cart,  is  the  largest  and  superior.  It 
consists  of  two  quadrilat.  plates,  or  alee,  united  in 
front  forming  the  pomum  Adami,  and  separated  poste- 
riorly to  receive  the  post  ext.  of  the  cricoid  cart. 
The  upper  edge  is  irregularly  convex,  and  is  j  oined  by 
the  thyro  hyoid  lig.  to  the  os  hyoides;  its  inf.  edge  is 
nearly  straight,  having  a  slight  projection  about  its 
centre,  and  is  connected  to  the  first  ring  of  the  tra- 
chea by  an  elastic  tissue,  the  crico-thyroid  ligament. 
The  posterior,  or  free  margin  rounded,  is  prolonged 
superiorly  into  the  greater  or  superior  cornu,  at- 
tached to  the  os  hyoides  by  a  round  and  sometimes 
cartilaginous  ligament.  The  inferior  is  shorter,  and 
forms  an  articulation  on  the  side  of  the  cricoid  cart. 
The  outer  surface,  nearly  plane,  is  marked  by  an  ob- 
lique line,  to  which  the  sterno-thyroid  and  thyro- 
hyoid  muscles  are  attached ;  the  inner  surface  is  con- 
cave, and  covers  the  crico-arytsenoid  lateralis  and 
thyro-arytsenoid  muscles. 

The  cricoid  cartilage  is  ring-shaped,  and  lies  be- 
neath the  preceding.  Narrow  in  front,  deep  behind, 
it  fills  here  the  interval  between  the  alas  of  the  thyroid 
cart.;  its  outer  surface  convex,  gives  origin  to  the  cri- 
co  thyroid  muse,  and  more  posteriorly  articulates  with 
the  inf.  cornu  of  the  thyroid  cart.  ;  behind  this  the 
posterior  surface  gives  origin  to  the  crico-ary  tsenoidei 
postici  muscles,  between  which  is  a  prominent  ridge ; 
the  inner  surface  is  lined  by  mucous  memb.,the  supe- 


28  EPIGLOTTIC  GLAND. 

rior  edge  of  the  cricoid  cart,  slopes  upwards  and 
backwards,  and  is  marked  by  a  convex  articulating 
surface  for  the  arytaenoid  cartilage. 

The  arytsenoid  cartilages  are  triangular  in  shape,  the 
base  is  concave,  and  rests  on  the  edge  of  the  cricoid 
cart. ;  on  it  are  two  projections,  one  ext.  for  the  in- 
sert, of  the  crico-arytamoid  muscle,  the  other  anterior 
for  the  attachment  of  the  true  chorda  vocalis ;  the 
apex  is  surmounted  by  the  appendix  or  corniculum. 
H\\Q  posterior  surface  concave,  lodges  the  inter  arytae- 
noid  muse. ;  the  anterior  convex  gives  attachment  to 
the  false  chorda  vocalis,  and  the  aryteno  epiglotti- 
dean  fold.  The  internal  surface  is  flat,  opposed  to 
its  fellow,  and  covered  by  mucous  membrane.  These 
cartilages  are  very  moveable,  and  thus  influence  the 
vocal  chords. 

The  epiglottis  is  situated  immediately  behind  the 
root  of  the  tongue,  and  over  the  upper  opening  of  the 
larynx ;  it  is  the  shape  of  an  oval  leaf,  concave  poste- 
riorly, and  covered  by  mucous  membrane ;  convex  in 
front,  it  is  attached  to  the  root  of  the  tongue  by  three 
folds  of  mucous  membrane,  theframum,  the  largest 
in  the  centre,  the  fraenula  on.  each  side;  to  its  edges 
are  attached  the  aryteno  epiglottidean  folds;  inferior- 
ly  the  epiglottis  ends  in  a  stalk-like  process,  which  is 
inserted  into  the  retreating  angle  of  the  thyroid  cart, 
above  the  chorda  vocalis.  The  use  of  the  epiglottis 
is  to  cover  the  glottis  in  the  act  of  deglutition;  it  is 
fibro-cartllaginous  in  structure. 

The  epiglottic  gland  lies  between  the  stalk-like  pro- 
cess of  the  epiglottis  and  the  thyro  hyoid  memb.  Its 
glandular  nature  is  very  questionable. 

The  larynx  is  connected  superiorly  to  the  os  hyoides 
by  the  thyro  hyoid  ligament;  this  is  best  marked  in 
the  centre  and  at  each  posterior  margin;  the  thyroid 
and  cricoid  cartilages  are  connected  in  front  by  the 
crico  thyroid  memb.  or  lig.;  this  is  strong,  and  of  a 
yellowish  colour;  a  capsular  ligament  connects  the 
articulation  between  the  cricoid  cart,  and  the  inf. 


MUSCLES  OF  LARYNX.  29 

cortiu  of  the  thyroid,  which  is  also  lined  by  synovial 
membrane. 

In  the  interior  of  the  larynx,  and  forming  the 
rima  glottidis,  are  the  chordae  vocales,  two  true  and 
two  false;  the  true  are  the  stronger  and  inferior, 
the  false  superior  and  less  distinct;  both  pass  from 
the  retreating  angle  of  the  thyroid  cartilage  to  the 
tubercle  on  the  base  of  the  arytaenoid,  the  false  one 
slightly  curved,  the  true  one  straight;  between  them 
is  a  small  fossa,  the  sacculus  laryngis ;  their  struc- 
ture is  fibrous.  The  use  of  the  chorda  vocalis  is  to 
open  and  close  the  rima  glottidis,  and  to  affect  the 
tones  of  the  voice  by  their  different  states  of  tension. 

Thyro-hyoideus,  Or.  oblique  ridge  of  ala  of  thyr. 
cartilage ;  Ins.  lower  border  of  cornu  of  os  hyoides. 
Use,  to  raise  and  draw  forwards  the  larynx  and 
close  the  glottis. 

Crico-thyroideus,  Or.  from  forepart  of  cricoid  cart.; 
Ins.  lower  edge  and  cornu  of  thyroid  cart.  Use,  to 
approximate  the  cartilages  and  make  tense  the  vocal 
chords. 

Thyro-arytenoideus,  Or.  inner  surface  of  thyroid 
cart. ;  Ins.  anterior  and  outer  edge  of  arytenoid 
cart.  Use,  to  draw  the  cartilages  towards  each 
other  and  narrow  the  rima  glottidis. 

Crico-arytenoideus  posticus,  Or.  from  concave  pos- 
terior surface  of  cricoid  cart. ;  Ins.  base  of  aryte- 
noid cart.  Use,  to  separate  the  chordae  vocales  and 
open  the  rima  glottis. 

Crico-arytenoideus  later alis,  Or.  side  of  cricoid  cart, 
near  its  upper  margin ;  Ins.  base  of  arytenoid  cart. 
Use,  to  open  the  rima  glottidis  and  relax  the  vocal 
chords. 

Arytenoidei.  Fill  the  concave  post,  surfaces  of 
the  arytenoid  cartilages,  they  consist  of  oblique  and 
transverse  fibres  passing  from  one  to  the  other. 
Use,  to  approximate  the  arytenoid  cart.,  close  the 
rima,  and  relax  the  vocal  chords. 

3* 


30  THE  PHARYNX. 

Some  muscular  fibres  are  occasionally  met  with 
in  the  thyro  epiglottie  and  aryteno-cpiglottic  folds, 
and  are  named  after  them.  They  are  of  little  im- 
portance. 

The  mucous  membrane  of  the  larynx  forms  a  por- 
tion of  the  bronchial  membrane,  and  resembles  it 
in  most  particulars ;  it  is  but  lobsely  connected  to 
the  subjacent  parts  by  loose  areolar  tissue. 

The  upper  opening  of  the  larynx  or  glottis  commu- 
nicates with  the  isthmus  faucium ;  triangular,  it  is 
bounded  in  front  by  the  epiglottis,  which  forms  its 
base,  its  apex  posteriorly  at  the  convergence  of  the 
arytenoid  cartilages,  its  sides  are  formed  by  the  % 
aryteno-epiglottic  folds. 

The  lower  opening  or  rima  glottidis,  a  narrow 
aperture,  slightly  triangular,  is  bounded  on  each 
side  by  the  true  chordae  vocales,  the  base  is  behind 
at  the  arytenoid  cartilages,  the  apex  in  front,  at  the 
retreating  angle  of  the  thyroid  cartilage,  where  the 
vocal  chords  arise.  The  rima  glottidis  is  liable  to 
much  and  constant  change;  the  glottis  varies  butlittle. 

The  arteries  of  the  larynx  are  derived  from  the  su- 
perior and  inferior  thyroid ;  the  nerves  are  branches 
of  the  par  vagum  or  pneumogastric  nerve;  of 
these  the  superior  laryngeal  enters  the  thyro  hyoid 
membrane,  and  is  distributed  to  the  arytenoid,  thyro 
arytenoid,  crico  arytenoid  lateralis,  and  crico  thy- 
roid muscles,  the  inferior  sends  filaments  to  the 
same  muse,  to  the  crico  arytenoid  posticus  and  anas- 
tomoses with  the  superior. 

SECTION   V. 
The  Pharynx. 

The  pharynx  is  a  musculo-membranous  tube,  of  a 
funnel  shape,  the  larger  extremity  being  continuous 
with  the  mouth  and  nares,  the  smaller  with  the  oeso- 
phagus ;  it  extends  from  the  base  of  the  cranium  to 


THE  PHARYNX.         .  31 

lie  4th  or 5th  cervical  vertebra;  its  length,  subject 
i  continual  variation,  is  about  four  inches  and  a 
lialf ;  its  upper  ext.  is  about  two  inches  wide,  and 
its  lower  one  eleven  lines.  The  following  chain  of 
iixed  points  affords  attachment  to  its  muscles.  The 
cricoid  and  thyroid  cartilages,  os  hyoides,  stylo- 
hyoid  ligament,  base  of  the  tongue,  infer,  maxilla, 
pterygo-maxillary  lig.  int.  pterygoid  plate  and  pet- 
rous bone;  behind,  they  are  attached  to  a  strong 
aponeurosis,  which  descends  from  the  basilar  pro- 
cess and  Eustachian  tubes. 

Constrictor  infer.;  Or.  1,  a  triangular  space  on  (he 
cricoid  cartilage,  between  the  crico  thyroid  and  ary- 
tsenoid  m.;  2,  the  oblique  line,  post,  and  sup.  edge, 
and  smaller  cornu  of  the  thyroid  cartilage;  Ins. 
with  its  fellow  into  the  raph6  on  the  back  part  of  the 
pharynx.  .•.  The  infer,  laryngeal  nerve  passes  be- 
neath its  lower  edge ;  the  super,  under  its  upper  edge. 
Constrictor  mcdius.  Triangular  by  its  apex  from 
the  body  and  cornua  of  the  os  hyoides  and  stylo  hy- 
oid  lig. ;  Ins.  by  its  base  with  its  fellow  into  the 
raphe.  •.  its  super,  fibres  are  continued  by  means  of 
a  pointed  tendon  to  the  basilar  process .  • .  the  stylo 
pharyngeus  m.  passes  under  its  upper  edge. 

Constrictor  super,  Or.  1,  base  of  the  tongue,  where 
it  is  continuous  with  the  genio  hyo  glossus,  2,  post, 
extremity  of  the  mylo  hyoid  ridge  ;  3,  pterygo  max- 
illary ligament ;  4,  lower  third  of  the  inner'  ptery- 
goid plate,  and  by  an  aponeurosis  from  the  petrous 
bone.  I?is.  tendinous  raphe  and  basilar  process .  • . 
an  oval  sinus  (Morgagni)  is  left  on  each  side,  be- 
tween its  upper  fibres  and  the  cranium.  The  phar- 
}Tnx  is  also  strengthened  by  fibres  from  the  petrous, 
basilar,  hamular,  and  styloid  process.  If  the  phar- 
ynx be  opened  by  an  incision  along  the  raphe,  there 
will  be  seen  the  velum,  isthmus  faucium,  base  of  the 
tongue,  epiglottis  and  seven  openings — viz.,  two  of 
the  nares,  two  Eustachian  tubes,  the  mouth,  the 
glottis,  and  the  oesophageal  entrance. 


32  THE  VELUM. 

The  pharynx  is  lined  literally  by  mucous  mem- 
brane, continuous  with  that  of  the  mouth,  larynx, 
&c.  This  is  covered  by  a  prolongation  of  the  cuticle 
termed  the  epithelium,  which  extends  as  far  as  the 
cardiac  extremity  of  the  oesophagus,  where  it  termi- 
nates in  a  fringed  margin. 

The  arteries  supplying  the  pharynx  are  derived 
from  the  pharyngea  ascendens  branch  of  the  ext. 
carotid,  the  tonsillitic  and  nasal  arteries ;  it  is  sup- 
plied with  nerves  from  the  pharyngeal  plexus  formed 
by  the  pharyngeal  branch  of  the  par  vagum,  the 
glosso  pharyngeal  and  sympathetic  nerves. 

In  deglutition  the  pharynx  is  first  opened  to  re- 
ceive the  morsel  of  food,  its  cavity  is  expanded  from 
before  backwards  by  the  elevation  of  the  larynx,  and 
from  side  to  side  by  the  stylo  pharyngei  and  palato 
pharyngei  muscle ;  the  morsel  of  food  having  de- 
scended into  it,  the  constrictor  muscles  contract 
from  above  downwards,  and  force  the  aliment  into 
the  oesophagus,  and  thence  it  passes  into  the  stomach. 

The  Velum  is  a  kind  of  septum,  projecting  back- 
wards and  downwards  from  the  posterior  edge  of  the 
palate  into  the  pharynx,  between  the  apertures  of  the 
mouth  and  nares;  its  muscles,  ten  in  no.,  are  inserted 
into  a  dense  aponeurosis,  usually  called  the  expansion 
of  the  tensor  palati  m.,  continued  from  the  fibrous 
portion  of  the  palate,  Eustachian  tubes,  and  septum 
nasi.  The  velum  is  raised  to  a  horizontal  line  by 

Levator  palati,  Or.  yarrow,  tendinous  from  the 
petrous  bone  near  its  summit,  and  the  adjoining 
portion  of  the  Eustachian  tube;  Ins.  broad  into  the 
post,  edge  of  the  aponeurosis,  and  with  its  fellow 
into  the  whole  length  of  the  median  line  beneath 
the  motores  uvulae. 

Cir cum flexus palati,  Or.  1, "scaphoid  fossa  atjthe  base 
of  the  int.  pterygoid  plate;  2,  adjoining  portions 
of  the  sphenoid  bone  and  Eustachian  tube :  it  first 
descends,  and  is  then  reflected  round  the  hamular 


THE  TONSIL.  33 

process,  running  horizontally  inwards  to  be  lost  in 
the  aponeurosis  palati  •.  -Separated  from  the  latter 
m.  by  the  sup.  constrictor. 

Motores  uvulse,  two  narrow  fasciculi,  descending 
along  the  median  line,  from  the  nasal  spine  to  the 
end  of  the  uvula-,  -behind  the  levator  palat.  The 
velum  is  depressed  by 

Palato  glossus,  Constrict,  isthma.  fauc.,  ant.  pillar 
of  the  fauces  narrow  in  the  middle,  its  super,  fibres 
are  expanded  with  those  of  the  following  muscle  into 
the  inf.  surface  of  the  velum,  and  its  inferior  are 
lost  with  the  stylo  glossus  in  the  side  of  the  tongue. 

Palato  pharyngeus.  post,  pillar  of  the  fauces  ;  Or. 
broad,  inf.  surface  of  the  palate,  and  whole  length 
of  the  median  line  of  the  velum;  Ins.  whole  length 
of  the  post,  edge  of  the  thyroid  cartilage,  and  into 
the  pharynx.-.  The  two  pillars  on  each  side  are  sepa- 
rated by  the  tonsil. 

The  velum  is  lined  on  both  surfaces  by  mucous 
membrane,  and  contains  numerous  glands,  vesseLs, 
and  nerves.  Its  arteries  are  derived  from  the  pala- 
tine branches  of  the  labial  and  int.  maxillary:  its 
nerves  are  branches  from  Meckel's  ganglion,  &c. 

From  the  centre  of  its  free  margin  depends  the 
uvula,  composed  of  a  few  muscular  fibres,  some 
glands  and  cellular  tissue ;  on  each  side  of  this  the  ve- 
lum is  curved  or  concave,  and  laterally  terminates  in 
two  projections  formed  by  the  palato  glossus  and 
palato  pharyngeus  muscles;  these  form  the  half  ar- 
ches of  the  palate,  and  separating  inferiorly  leave 
an  interval  in  wrhich  is  lodged  the  amygdala  or  tonsil. 

The  use  of  the  velum  is  to  prevent  the  food  from 
passing  upwards  into  the  nares  during  deglutition; 
in  this  act  it  is  raised  and  spread  out  so  as  to  present 
an  inclined  plane  forwards.  It  is  also  useful  in 
forming  the  sounds  of  the  voice. 

The  amygdala,  or  tonsil,  is  lodged  in  the  recess  be- 
tween the  half  arches  of  the  palate;  it  is  almond  sl;ap- 


34  EUSTACHIAN    TUBES. 

ed,  the  smaller  extremity  turned  downwards;  its 
structure  is  a  number  of  mucous  follicles,  connected 
by  cellular  tissue,  and  covered  by  mucous  membrane. 

The  Posterior  nares  lie  immediately  above  the 
velum,  each  is  quadrilateral  in  shape,  and  conveys 
the  air  from  the  anterior  nares  into  the  isthmus 
faucium  and  lungs. 

The  opening  of  the  Eustachian  tubes  are  situated 
one  on  each  side  of  the  posterior  nares,  opposite 
and  a  little  above  the  post,  extremity  of  the  inf. 
spongy  bone.  They  conduct  the  external  air  into 
the  cavity  of  the  tympanum. 


35 
CHAPTER  III. 

THE   UPPER    EXTREMITIES 

Are  attached  to  the  trunk  by  means  of  the  clavicle 
and  numerous  muscles ;  some  of  them  are  situated 
on  the  ant.  and  some  on  the  post,  surface. 

SECTION   I. 

Muscles  of  the  Anterior  and  Lateral  Parts  of  the  Trunk* 
Thorax. 

Pectoralis  major,  Or.  1,  sternal  half  of  the  clavicle; 
2,  ant.  surface  of  the  sternum;  3,  the  cartilages  of  all 
the  true  ribs,  except  the  first  and  last.  Ins.  into  the 
ant.  lip  of  the  bicipital  groove  by  a  double  tendon;  the 
ant.  portion  of  which  receives  the  upper  and  middle 
fibres,  the  posterior  the  infer,  fibres.  Use,  to  draw 
the  arm  inwards  to  the  side,  and  rotate  it  inwardly; 
the  clavicular  portion  raises  the  arm;  if  this  be  fixed 
the  sternal  and  costal  portions  will  assist  in  inspira- 
tion. 

Pectoralis  minor,  Or.  third,  fourth,  and  fifth  ribs, 
just  beyond  their  cartilages;  Ins.  into  the  point  of 
the  coracoid  process.-,  crosses  the  middle  of  the  ax- 
illary vessels  and  nerves.  Use,  to  depress  the  glenoid 
cavity  inwards,  also  to  assist  in  inspiration. 

Subclavius,  fusiform,  Or.  by  a  flat  tendon  from  the 
cartilage  of  the  first  rib.  Ins.  ext.  half  of  the  inf.  sur- 
face of  the  clavicle-,  -covered  by  a  strong  aponeurosis 
(costo-coracoid  ligament)  which  arches  over  the  ves- 
sels and  muscle  from  its  attachment  to  the  clavicle 
to  the  coracoid  process.  Use,  to  depress  the  clavicle 
and  shoulder  inwards,  to  raise  the  first  rib. 

Serratus  magnus,  Or.  by  nine  or  ten  digitations 
from  the  ten  sup.  ribs.  The  first  portion  arises  by 


36  MUSCLES  OF   THORAX. 

one  digitation  from  the  first  and  second  rib,  is  Ins. 
into  the  sup.  angle  of  the  scapula;  a  second  portion 
by  three  digit,  from  the  second,  third,  and  fourth  ribs, 
Ins.  into  the  base  of  the  scapula;  third  portion  by  six 
digit,  from  fifth,  six,  seventh,  eighth,  ninth,  and  tenth 
ribs,  Ins.  into  the  inf.  angle  of  the  scapula-. 'the  five 
inf.  digitations  intersect  with  five  of  the  obliquus  de- 
scend, m.  Ins.  between  the  subscapularis  and  the 
rhomboidei  and  levat.  scapulae.  Use,  to  draw  for- 
wards the  scapula,  to  assist  in  inspiration — the  sup. 
fibres  depress  the  glenoid  cavity — the  inf.  fibres  ele- 
vate it  by  rotating  the  scapula. 

Inter  costales,  eleven  internal  and  eleven  external, 
on  each  side.  They  are  attached  to  the  opposite  edges 
of  each  pair  of  ribs.  The  fibres  of  the  ext.  extend 
from  the  transverse  processes  of  the  vertebras  to  the 
costal  end  of  the  ribs,  and  by  an  aponeurosis  from 
that  point  to  the  sternum:  those  of  the  internal  ex- 
tend from  the  sternum  to  the  angles  of  the  ribs, 
and  from  that  point  by  an  aponeurosis  to  the  spine.-, 
the  intercostal  vessels  and  nerves  separate  the  two 
layers,  -.the  fibres  of  the  ext.  run  downwards  and  out- 
wards in  the  direction  of  the  obliq.  extern,  abdom-.- 
the  internal  in  a  contrary  direction  like  the  ob.  int. 
abd.  Use,  to  raise  the  ribs  in  inspiration. 

Levatorcs  costarum,  triangular,  twelve  on  each  side, 
Or.  pointed  from  a  transverse  process  above.  Ins. 
broad  ext.  surface  of  the  rib  next  below.  Use,  to 
raise  the  ribs.  f 

Triangular  stcrni,  (serrat.  min.  antic.)  Or.  post, 
surface  and  edges  of  the  lower  part  of  the  sternum, 
xiphoid,  and  adjoining  costal  cartilages.  Ins.  by  dis- 
tinct digitations  into  the  inf.  margins  of  the  sixth, 
fifth,  fourth,  and  third  costal  cartilages.  Use,  to  de- 
press the  costal  cartilages  in  expiration. 


MUSCLES   OF   BACK.  37 

SECTION  II. 

Muscles  on  the  Posterior  part  of  the  Trunk. 
Dorsal  muscles — First  layer,  2. 

Trapezius.  Or.  1,  thin  and  aponeurotic  from  the  in- 
ner third  of  the  sup.  occip.  ridge;  2,  the  twelve  dorsal 
spinous  processes;  3,  from  the  last  cervical  spine,  and 
the  ligamentum  nuchoe,  which  extends  from  that  pro- 
cess to  the  occipital  protuberance.  Ins.  the  spine  of 
the  scapula,  the  acr omion  process  and  the  ext.  third  of 
the  clavicle. '.from  the  same  extent  of  the  latter  pro- 
cesses arises  the  deltoid.  The  tendinous  fibres  of  the 
two  muscles,  from  the  sixth  cervical  to  the  third  dorsal 
vertebrae,  represent  an  ellipsis.  Use,  to  elevate  the 
shoulder,  to  depress  the  head  backwards  and  to  one 
side ;  the  sup.  fibres  raise  the  glenoid  cavity  directly, 
the  inf.  fibres  rotate  the  scapula  and  so  raise  the 
glenoid  cavity;  to  fix  the  scapula  and  thus  antagonize 
the  serratus  magnus  in  inspiration. 

Latissimus  dorsi,  Or.  from  the  six  inferior  dorsal 
spinous  processes,  by  a  strong  fascia,  which  is  con- 
founded with  that  of  the  int.,  obliq.  and  transversalis 
m.;  from  the  spines  of  the  lumbar  vertebrae  and  sa- 
crum, and  the  post,  third  of  the  crista  ilii:  lastly,  by 
so  many  digitations  from  the  three  or  four  last  ribs; 
Ins.  the  inner  and  post,  edge  of  the  bicipital  groove  in 
front  of  the  teres  major,  '.its  costal  attachments  inter- 
digitate  with  the  digitations  of  the  ext.  obliq.;  some- 
times an  additional  slip  arises  from  the  inf.  angle  of 
the  scapula.  Use,  to  draw  the  arm  backwards  and  in- 
wards, so  as  to  rotate  the  palm  of  the  hand  inwardly; 
to  compress  the  side  of  the  thorax  in  respiration ;  to 
assist  in  raising  the  ribs  if  the  arm  be  previously 
fixed. 

Second  Layer,  3. 

Rhomboidei,  \,  R.  major,  Or.  four  or  five  sup.  dorsal 
spines;  Ins.  base  of  the  scapula,  from  its  spine  to  .its 
4 


38  MUSCLES    OF   BACK. 

inf.  angle;  2,  R.  minor,  Or.  last  cerv.  spine;  Ins. 
base  of  the  scapula,  between  the  two  roots  of  the  spi- 
nous  process.  Use,  to  draw  backwards  the  scapula, 
and  depress  the  glenoid  cavity. 

Lcvator  anyuli  scapula,  Or.  post,  transverse  tuber- 
cles of  the  three  or  four  sup.  cerv.  vert.;  Ins.  into  the 
angle  of  the  scapula,  and  its  post,  edge  as  far  as  the 
spine.  Between  the  splenius  colli  and  the  scaleni  and 
rect.  capit.  ant.  Use,  to  raise  the  sup.  angle  of 
scapula,  and  depress  the  glenoid  cavity. 

Third  Layer,  4. 

Serratuspost.  superior,  Or.  lig.  iiuchse,  first  cervical, 
and  second  or  third  upper  dorsal  spines;  Ins.  by  slips 
into  the  second,  third  and  fourth  ribs,  beyond  their 
angles.  Use,  to  raise  these  ribs. 

Scrratus  post,  inferior,  Or.  two  last  dorsal  and  three 
upper  lumbar  spines;  Ins.  the  four  last  ribs,  just  be- 
yond their  angles.  A  fine  but  strong  aponeurosis  is 
stretched  from  one  muscle  to  the  other;  which  inter- 
nally is  attached  to  the  spinal  processes,  externally  to 
the  ribs,  beyond  their  angles.  Use,  to  depress  the 
lower  ribs  in  expiration. 

Splenius  colli  et  capitis,  both  muscles  arise  from  tfye 
two  or  three  upper  dorsal  and  the  last  cervical  spines, 
and  from  the  ligament,  nuchge,  as  far  as  the  third  cer- 
vical spine;  Ins.  the  s.  colli  into  the  post,  trans,  tuber- 
cles of  the  first  and  second,  sometimes  the  third  cervi- 
cal vertebras;  the  5.  capitis  into  the  post,  edge  of  the 
mast oid  process,  and  adj  oining  third  of  the  rough  sur- 
face between  the  two  occipital  curved  lines.-. S.  colli, 
at  its  insertion,  is  behind  the  L.  ang.  scap.  Use,  to 
bend  the  head  and  neck  backwards. 

Fourth  Layer. 

The  fourth  layer  is  entirely  covered  by  the  above 
muscles  and  their  fascia. 


MUSCLES    OF  BACK.  39 

Longissimus  dorsi.  The  mass  of  muscle  bearing  this 
name  fills  up  the  interval  between  the  spinous  pro- 
cesses and  ribs,  where  it  is  bound  down  by  the  serratus 
fascia;  in  the  lumbar  region  it  is  ensheathed  by  the 
superficial  and  middle  lumbar  fascia;  in  this  situation 
the  muscle  constitutes  the  common  origin  of  three  dis- 
tinct muscles  and  their  cervical  prolongations.  It  is 
attached,  fleshy,  to  the  whole  surface  of  the  sacroiliac 
groove,  and  to  the  anterior  surface  of  a  dense  fascia, 
which  is  attached  to  the  post,  third  of  the  crista  ilii 
and  its  posterior  spinous  processes,  and  to  those  of  the 
sacrum,  lumbar,  and  three  last  dorsal  vertebrae. 

Sacro  lumbalis  (the  external  division,)  Or.  from  the 
common  mass;  Ins.  by  distinct  tendons  into  the  six 
last  ribs,  near  their  angles;  here  it  would  cease,  but 
the  musculi  accessorii,  arising  by  distinct  tendons  from 
all  the  ribs  successively  from  the  last,  join  the  muscle 
so  as  to  enable  it  to  deposit  similar  tendons  on  the 
angles  of  the  six  upper  ribs,  and  to  ascend  in  the 
neck  under  the  name  of 

Cervicalis  ascendens.  It  is  formed  by  the  fourth  or 
fifth  upper  musculi  accessorii  •  Ins.  post,  transverse  tu- 
bercles of  the  fourth,  fifth,  and  sixth  cervical  ver- 
tebrae. 

Longissimus  dorsi  (middle  division,)  Or.  from  the 
common  mass;  Ins.  internally  into  the  transverse  pro- 
cesses of  all  the  dorsal,  and  into  the  spinous  processes 
of  the  five  or  six  upper  dorsal  vertebrae  ;  and  exter- 
nally into  all  the  ribs  between  their  tubercles  and  an- 
gles. It  is  prolonged  into  the  neck  as  the 

Tranversalis  cervicis.  Its  origin  is  formed  by  mus. 
access,  from  the  third,  fourth,  fifth  and  sixth  dorsal 
transverse  process ;  Ins.  into  the  post,  tubercles  of  the 
third  or  fourth  upper  cervical  transverse  processes, 
between  the  cerv.  ascend,  and  trachelo  mastoideus. 

Spinalis  dorsi  (inner  division,)  Or.  from  the  inner- 
most portion  of  the  common  mass,  which  reaches  as 
high  as  the  ninth  dorsal  vert.;  Ins.  into  the  spinous 


40  MUSCLES    OF    BACK. 

processes  of  the  nine  superior  ribs;  its  cervical  pro- 
longation is  the 

Spinalis  colli.  It  arises  by  mus.  actessorii  from  the 
transverse  processes  of  the  five  dorsal  vertebrae,  to 
be  Ins.  into  the  spinous  processes  of  the  six  last  cervi- 
cal.-, it  is  covered  by  the  complexus.  A  deeper 
seated  portion  of  the  spinalis  dorsi,  from  the  dimi- 
nished length  of  its  fasciculi,  is  called 

Semi  spinalis  dorsi.  It  arises  from  the  dorsal  trans- 
verse processes,  from  the  fifth  to  the  eleventh ;  Ins.  to 
the  spinous  processes  of  the  three  super,  dorsal  and 
two  inf.  cervical  vertebrae.  Deeper  still,  the  fasciculi 
are  much  shorter,  and  are  called 

Multifidus  spinze ;  Or.  by  slips  from  all  the  trans- 
verse pr.,  between  the  first  sacral  and  the  third  dorsal 
vert.;  each  slip  is  Ins.  into  the  first,  second,  or  third 
spinous  process  next  above ;  the  last  is  attached  to 
the  spine  of  the  axis. 

Complexus,  Or.  1,  five  or  six  upper  dorsal  trans- 
verse processes;  2,  four  last  cervical  articulating  pro- 
cesses; 3,  spinous  processes  of  the  last  cervical,  and 
two  upper  dorsal.  Ins.  inner  half  of  the  rough  sur- 
face between  the  occipital  ridges. 

Trachelo  mastoideus  (complexus  minor,)  Or.  trans, 
processes  of  the  four  last  cervical  and  four  uppe'r 
dorsal  vertebrae;  Ins.  back  part  of  the  mastoid  pro- 
cess, beneath  the  splenius. 

Fifth  Layer. 

Inter  spinales.  Double,  in  the  cervical ;  single,  in 
tl^e  lumbar  and  dorsal  vertebrae.  Indistinct  in  the 
latter. 

Inter  transversalis.  Double,  in  the  cervical;  single, 
in  the  lumbar  and  dorsal  vertebrae.  Indistinct  in  the 
latter.  The  principal  use  of  the  deep  spinal  muscles 
is  to  fix  the  spinal  column,  and  move  its  several  por- 
tions slightly;  they  are  antagonistic  to  most  of  the 
other  muscles  attached  to  the  spine. 


SUPERIOR   EXTREMITY.  41 

Rectus  posticus  major,  Or.  narrow  from  the  spine  of 
the  axis;  Ins.  broad  into  the  inf.  occipital  trans- 
verse ridge.  Use,  to  depress  the  head  posteriorly. 

Rectus  posticus  minor,  Or.  narrow  from  the  spine 
of  the  atlas;  Ins.  broad  into  the  occipital  bone,  be- 
hind the  foramen  magnum.  Use,  to  depress  the  head 
backwards. 

Obliquus  inf.,  Or.  narrow  from  the  spine  of  the 
axis;  Ins.  narrow,  end  of  the  transverse  process  of 
the  atlas.  Use,  to  rotate  the  atlas  and  head  on  the 
second  vertebrae. 

Obliquus  super.,  Or.  narrow,  from  the  transverse 
process  of  the  atlas ;  Ins.  broad  into  the  rough  sur- 
face between  the  occipital  ridges  just  behind  the 
mastoid  process.  Use,  to  bend  the  head  backwards 
and  to  one  side. 

SECTION  III. 
Superior   Extremity. 

Immediately  beneath  the  skin  and  subjacent  cellu- 
lar tissue  the  muscles  of  the  arms  and  side  of  the  thorax 
will  be  found,  covered  with  a  tolerably  dense  layer  of 
fascia,  which  descends  from  a  spine  of  the  scapula, 
the  acromion  process,  and  clavicle,  to  invest  them.  It 
is  best  marked  on  the  inner  side  of  the  arm,  where  it 
covers  the  brachial  vessels  and  nerves,  and  on  the  ant. 
surface  of  the  biceps  muse.  It  is  firmly  attached  to 
the  lower  margins  of  the  pectoralis  major  and  latis- 
simus  dorsi,  and  passes  from  these  across  the  floor 
of  the  axilla,  so  as  to  close  and  protect  its  cavity.  In- 
feriorly,  the  brachial  aponeurosis  is  attached  to  the 
intermuscular  septa,  and  the  condyles  of  the  humerus. 

Muscles  of  the  Shoulder,  5. 

Deltoideus,  Or.  1,  from  the  whole  extent  of  the  post. 

border  of  the  spine  of  the  scapula;  2,  the  acromion 

process;  3,  the  ext.  third  of  the  clavicle.  Ins.  narrow, 

into  a  triangular  surface  on  the  outer  side  of  the  hu- 

4* 


42  MUSCLES   OF    SCAPULA. 

merus  a  little  above  its  middle,  between  the  two  heads 
of  the  brachialis  anticus  m.  '.separated  from  the  pec- 
toralis  major  by  the  descending  branch  of  the  thor- 
acic acromialis  art.  and  the  cephalic  vein.  Use,  to 
raise  the  arm  from  the  side,  or  to  depress  the  shoulder. 
The  ant.  fibres  draw  it  forwards ;  the  post,  backwards. 

Supra  spinatus,  Or.  the  inner  two-thirds  of  the  fossa 
supra  spinat.;  Ins.  super,  facette  of  the  larger  tuber- 
cle of  the  humerus.  Use,  to  raise  and  abduct  the  arm. 

Infra  spinatus,  Or.  inf.  surface  of  the  spine,  and 
the  dorsum  of  the  scapula  as  far  as  the  post,  of  the 
two  ridges  on  its  inf.  costa;  Ins.  middle  facette  of 
the  larger  tubercle  of  the  humerus.  Use,  to  raise 
the  arm,  and  draw  it  backwards. 

Teres  minor  Or.  inf.  costa  of  the  scapula,  between 
its  two  ridges  ;  Ins.  inferior  facette  of  the  larger  tu- 
bercle of  the  humerus.  The  tendons  of  these  three 
muscles  cover  the  head  of  the  humerus,  and  are  inti- 
mately adherent  to  the  capsule  of  the  joint.  Use, 
similar  to  the  preceding.  The  principal  use  of  the 
three  capsular  muscles  is  to  support  the  articula- 
tion, and  keep  the  head  of  the  humerus  in  situ. 

Teres  major,  Or.  form  a  flat  quadrilateral  surface 
on  the  inf.  angle  of  the  scapula;  Ins.  post,  marghrof 
the  bicipital  groove,  behind  the  tendon  of  the  latissi- 
mus  dorsi.  Use,  to  draw  the  arm  downwards,  back- 
wards, and  to  the  side;  to  rotate  it  inwards  ;  and 
when  the  arm  is  fixed,  to  draw  forwards  the  inf. 
angle  of  the  scapula,  and  elevate  the  glenoid  cavity. 

The  two  teres  muscles,  in  proceeding  to  their  in- 
sertions, leave  an  opening  between  them,  which  is 
divided  into  two  by  the  passage  of  the  long  head  of 
the  triceps;  the  anter.  one  transmits  the  post,  cir- 
cumflex artery  and  nerve;  the  other  the  r.  dorsalis 
scapulae  of  the  infra  scap.  art.  and  nerve. 

Subscapularis  Or.  subcapular  fossa  and  its  mar- 
gins ;  Ins.  the  inner  or  smaller  tubercle  of  the  hu- 
merus to  keep  the  head  of  the  humerus  and  glenoid 
cavity  in  close  apposition. 


MUSCLES    OF   ARM.  43 

Muscles  of  the  Arm  :  in  front,  3 ;  Flexors. 

Coraco  brachialis,  Or.  from  the  tip  of  the  coracoid 
process  in  conjunction  with  the  short  head  of  the 
biceps,  to  which  it  is  attached  for  some  way  down; 
Ins.  into  the  inner  side  of  the  humerus,  opposite  to 
the  insertion  of  the  deltoid  ;  it  first  covers  and  then 
runs  along  the  outer  side  of  the  art.  brachial :  per- 
forated by  the  ext.  cutan.  nerve.  Use,  to  raise, 
draw  forwards,  and  rotate  the  arm  outwards. 

Biceps,  Or.  the  short  head,  from  the  tip  of  the  cora- 
coid process  with  the  coraco  brachialis  m. ;  the  long 
head,  from  the  upper  edge  of  the  glenoid  cavity  where 
its  tendon  bifurcates,  its  division  descending  on  the 
margins  of  that  cavity  to  meet  similar  divisions  on  the 
long  head  of  the  triceps.  Ins.  by  a  strong  flat  tendon, 
which  is  twisted  half  around,  into  the  tubercle  of  the 
radius:  just  before  the  tendon  sinks  to  its  insertion, 
it  gives  on7  the  semilunar  fascia,  which  crosses  the  pro- 
nator  teres,  to  strengthen  the  fascia  of  the  fore  arm.  •. 
The  long  head  is  enclosed  in  the  capsular  ligament  of 
the  shoulder  joint,  but  outside  of  the  synovial  mem- 
brane, which  accompanies  it  for  some  way  down  the 
groove,  -.its  inner  edge  constitutes  an  unerring  guide 
to  the  brachial  artery.  Use,  to  flex  the  fore  arm  on 
the  arm,  to  make  tense  the  fascia,  and  rotate  the  ra- 
dius outwards;  also  to  depress  the  glenoid  cavity 
and  scapula. 

brachialis  anticus,  Or.  1,  by  two  angular  slips  which 
embrace  the  insertion  of  the  deltoid;  2,  from  the 
condyloid  ridges  of  the  humerus,  and  anterior  sur- 
face between  them,  down  to  the  elbow  joint.  Ins. 
coronoid  process  of  the  ulna,  and  rough  surface  be- 
yond. Use,  to  flex  the  fore  arm. 

Back  part  of  the  Arm,  1,  Extensor. 

Triceps,  Or.  1,  its  long  head,  by  a  flat  tendon  from 
the  lower  edge  of  the  neck  of  scapula,  where  itbifur- 


44  ARTERIES  AND  NERVES  OF  ARM. 

cates  to  join  the  divisions  of  the  biceps;  2,  middle 
head,  from  the  post,  and  ext.  surface  of  the  humerus, 
between  the  spiral  groove  and  insertion  of  the  teres 
minor,  and  from  the  ext.  condyloid  ridge  and  aponeu- 
rotic  septum,  as  far  as  the  condyle ;  3,  the  small  head, 
from  the  int.  and  post,  surface  of  the  humerus,  below 
the  spiral  groove  and  insertion  of  the  teres  major  m., 
and  from  the  int.  condyloid  ridge  and  intermuscular 
septum.  Ins.  by  a  strong  aponeurosis  into  the  olecra- 
non. -.the  spiral  groove  commences  above  the  small 
head,  winds  in  front  of  the  long  head,  and  below  the 
super,  attachments  on  the  middle  head.  Use,  to  extend 
the  fore  arm,  and  depress  the  neck  of  the  scapula. 
The  long  head  separates  the  two  spaces  beneath  the 
inf.  margin  of  the  scapula ;  its  second  and  third  heads 
are  separated  by  the  musculo  spinal  or  radial  nerve. 

In  the  dissection  of  the  muscles  of  the  shoulders  and 
arm,  numerous  vessels  and  nerves  are  met  with.  The 
arteries  are  branches  of  the  subclavian,  the  superior 
scapular,  and  posterior  scapular ;  of  the  axillary,  the 
thoracica  acromialis,  thoracica  suprema,  glandulares 
thoracica  longa  or  submammary,  the  subscapular, 
and  the  anterior  and  posterior  circumflex ;  of  the 
brachial,  the  superior  profunda,  inferior  profunda, 
and  anastomatica  magna. 

The  superior,  posterior,  and  subscapular  arteries, 
as  their  names  imply,  surround  the  margins  of  the 
scapula,  and  sending  branches  to  the  muscles  on  both 
of  its  surfaces,  anastomose  freely  together,  and  thus 
establish  an  intimate  connexion  between  the  subcla- 
vian and  axillary  arteries  ;  and  by  no  means  of  their 
subanastomoses  with  the  carotid  arteries  above  and 
the  brachial  arteries  beneath,  are  of  essential  impor- 
tance in  tying  any  one  of  these  vessels.  The  remain- 
ing branches  of  the  axillary,  excepting  the  circumflex 
are  found  connected  with  the  pectoral  muscles,  and 
cavity  of  the  axilla ;  these  anastomose  freely  also  with 
the  vessels  about  the  shoulder  externally,  and  the 


MAMMARY  GLAND.  45 

>racic  and  intercostal  arteries  internally,  as  to  keep 
up  the  circulation  when  one  or  other  of  the  large 
trunks  is  tied.  The  circumflex  arteries  surround  the 
neck  of  the  humerus,  and  are  chiefly  lost  in  the  deltoid. 

The  nerves  of  this  region  are  principally  derived 
from  the  brachial  plexus ;  they  are  anterior  and  pos- 
terior thoracic  to  the  thoracic  muscles,  the  circumflex 
to  the  deltoid,  the  suprascapular  to  the  fossa  of  the 
same  name,  the  subscapular  to  the  subcap.  muscle, 
and  sending  a  few  filaments  to  the  dorsal  surface  of 
the  scapula,  and  lastly,  the  nerves  to  the  arm  and  fore- 
arm, viz.,  on  the  outer  side  the  ext.  cutaneous  and 
median,  on  the  inner  the  int.  cutaneous  and  ulnar, 
and  posteriorly  the  musculo-spiral  or  radial.  Some 
small  nervous  filaments  are  met  with  in  the  subcuta- 
neous cellular  tissue ;  these  are  chiefly  on  the  inner 
side,  and  consists  of  branches  from  the  internal  cuta- 
neous, and  the  nerves  of  Wrisberg,  derived  from  the 
2nd  and  3rd  intercostals. 

The  principal  veins  are  the  cephalic  and  basilic, 
and  the  brachial  trunk.- 

The  Axilla,  or  Axillary  cavity  is  triangular,  its 
apex  superiorly  at  the  coracoid  process;  the  base  infe- 
riorly  formed  by  the  axillary  fascia,  stretching  from 
thepect.  major  to  the  latissimus  dorsi;  it  is  bounded 
in  front  by  the  pectoral  muscles,  behind  by  the  sub- 
scap.  muse.,  internally  by  the  serratus  magnus,  ex- 
ternally by  the  neck  of  the  hurnerus ;  it  contains 
the  axillary  artery  and  vein,  and  their  principal 
branches,  and  the  axillary  plexus  of  nerves,  the  con- 
tinuation of  the  brachial  plexus  embeded  in  cellular 
tissue  and  a  number  of  lymphatic  glands. 

In  the  female  subject,  the  Mammary  Glands  are 
found  one  to  each  side  resting  on  the  pectoralis  ma- 
j  or  muscle  to  which  they  are  loosely  connected  by  ar  eo- 
lar  tissue.  The  mammary  gland  is  hemispherical  in 
shape,  convex  in  front,  flat  posteriorly:  it  is  composed 
of  a  number  of  distinct  lobules,  separated  by  condensed 


46  THE  FORE-ARM. 

cellular  tissue,  and  some  adipose  substance.  Each 
lobule  is  composed  of  a  number  of  granules,  from 
which  the  lacteal  ducts  proceed,  and  gradually  uni- 
ting open  upon  the  free  extremity  of  the  nipple.  This 
is  a  slightly  conical  projection,  composed  of  the  in- 
teguments, lacteal  ducts,  and  erectile  areolar  tissue ; 
it  is  surrounded  by  an  areole  of  the  integuments, 
generally  of  a  brownish  colour,  but  in  the  young  fe- 
male, unimpregnated,  is  of  a  pinkish  hue;  on  this 
open  a  number  of  sebaceous  follicles. 

The  mammary  gland  is  supplied  with  blood  from 
the  thoracic  branches  of  the  axillary,  the  intercos- 
tal, and  the  internal  mammary.  The  nerves  are  de- 
rived from  the  brachial  plexus  and  the  intercostals. 
Its  absorbents  are  very  numerous,  and  communicate 
with  the  axillary,  cervical,  and  thoracic  glands. 

SECTION  IY. 
Of  the  fore-arm. 

The  fore-arm  extends  from  the  elbow  to  the  wrist- 
j  oint ;  it  is  covered  by  the  integuments,  beneath  which 
lies  a  quantity  of  loose  cellular  tissue  in  which  are 
found  in  front,  the  superficial  veins — viz.,  the  cepha- 
lic on  the  outer,  the  basilic  on  the  inner  side,  and 
median  in  the  centre,  and  superficial  nerves  branches 
of  the  int.  and  ext.  cutaneous ;  on  the  back  part,  also, 
some  superficial  veins  and  nerves,  the  latter  branches 
of  the  ext.  cutaneous  and  musculo-spiral  nerves. 

Beneath  this  is  the  ant.  brachial  aptneuratis,  or 
fascia,  exceedingly  dense,  investing  the  muscles,  and 
sending  septa  between  so  as  to  separate  them  from 
each  other ;  it  is  attached  superiorly  to  the  condyles 
of  the  humerus,  intermuscular  septa  and  tendon  of 
the  biceps,  on  the  inner  side  to  the  spine  of  the  ulna, 
and  inferiorly  to  the  ant.  and  post,  annular  ligaments 
of  the  wrist. 


MUSCLES    OF   TORE-ARM.  47 

Muscles  of  the  Fore  Arm,  in  front,  8. 
Superficial  set,  5,  which  arise  from  the  inner  condyle. 

Pronator  teres,  Or.  1,  the  inner  condyle  and  inter- 
muscular  septa;  2,  from  the  coronoid  process  of  the 
ulna.  Ins.  outer  edge  of  the  radius,  at  its  middle.'. 
The  median  nerve  passes  between  its  two  origins.  Use, 
to  flex  the  fore  arm,  and  rotate  the  radius  inwards. 

Flexor  carpi  radialis,  Or.  inner  condyle  and  septa; 
Ins.  base  of  the  second  metacarpal  bone.  Use,  to  flex 
the  fore  arm  and  hand. 

Palmaris  longus,  Or.  inner  condyle  and  septa;  Ins. 
annular  ligament  and  palmar  fascia.  Use,  to  make 
tense  the  palmar  aponeurosis  and  flex  the  hand. 

Flexor  carpi  ulnaris,  Or.  1,  inner  condyle;  2,  inner 
edge  of  the  olecranon;  3,  by  an  aponeurosis  from  the 
upper  two-thirds  of  the  inner  edge  of  the  ulna.  Ins. 
pisiform  bone,  its  fibres  strengthening  the  ligament 
which  unites  that  bone  to  the  os  pyramidale.  -.the  ul- 
nar  nerve  passes  between  the  first  and  second  origins: 
its  inner  edge  is  a  guide  to  the  lower  two-thirds  of 
the  ulnar  artery.  Use,  to  flex  the  hand. 

Flexor  sublimis  perforatus,  Or.  1,  inner  condyle;  2, 
the  inner  edge  of  the  coronoid  process  of  the  ulna;  3, 
upper  part  of  the  oblique  ridge  of  the  radius.  Ins. 
into  the  fingers  by  four  tendons,  which  split  at  the 
end  of  the  first  phalanx,  to  give  passage  to  the  tendons 
of  the  deep  flexor;  each  division  then  winds  round 
the  edges  of  the  corresponding  tendon  of  the  latter 
muscle,  so  as  to  form  a  kind  of  sheath  for  it,  and 
both  are  then  inserted  close  together  into  the  fore 
part  of  the  second  phalanx.  Use,  to  flex  the  fingers 
on  the  hand,  and  this  on  the  wrist. 

Deep  seated  Muscles,  3. 

Flexor profundusperforans,  Or.  1.  ant.  three-fourths 
of  the  fore  part  of  the  ulna  and  inner  edge  of  the  coro- 
noid process;  2,  inner  half  of  the  interosseous  liga- 


48  MUSCLES  OF  FORE-ARM. 

ment;  3,  by  a  slip  from  the  radius,  just  below  its  tu- 
bercle. Ins.  by  four  tendons,  each  of  which  perfo- 
rates a  corresponding  tendon  of  the  last  m.,  and  is 
inserted  into  the  last  phalanx.  Use,  to  flex  the  fin- 
gers on  the  hand,  and  this  on  the  wrist. 

Flerxo  longus  pollicis  Or.  1,  ant.  surface  of  the  ra- 
dius, from  its  tubercle  to  the  upper  edge  of  the  pro- 
nator  quadratus ;  2,  outer  half  of  the  interosseous 
ligament,  Ins.  last  phalanx  of  the  thumb.  Use,  to 
flex  the  thumb. 

Pronator  quadratus  Or.  lower  fifth  of  the  anterior 
surface,  and  inner  edge  of  the  ulna ;  Ins.  ant.  surface 
and  inner  and  outer  edges  of  the  lower  fourth  of  the 
radius.  Use,  to  pronate  the  radius  and  hand. 

Muscles  on  the  outer  edge,  4. 

Supinator  radii  longus,  Or.  ext.  conclyloid  ridge  of 
the  humerus  and  intermuscular  septum,  from  the 
spiral  groove  to  within  two  inches  of  the  condyle ;  Ins. 
into  the  styloid  process  of  the  radius.*. the  lower  two 
thirds  of  the  radial  artery  run  along  the  inner  edge 
of  its  tendon.  Use,  to  supinate  the  hand. 

Extensor  carp,  radialis  longior,  Or.  from  the  lower 
part  of  the  external  condyloid  ridge,  and  the  external 
condyle ;  Ins.  post,  surface  of  the  carpal  end  of  the 
second  metacarpal  bone. 

Ext.  carp.  rad.  brevior,  Or.  post,  part  of  the  exter- 
nal condyle,  with  the  common  extensor:  Ins.  post,  sur- 
face of  the  carpal  end  of  the  third  metacarpal  bone. 

Supinator  radii  brevis,  Or.  1,  from  the  outer  condyle 
by  the  common  tendon ;  2,  from  the  ext.  lateral  and 
annular  ligaments :  3,  from  a  ridge  on  the  ulna  and 
triangular  fossa  in  front  of  it.  Ins.  into  the  fore-part, 
and  outer  and  back  part  of  the  radius,  in  a  line  lead- 
ing obliquely  from  above  its  tubercle  to  the  ins.  of  the 
pronator  teres.  Pierced  by  the  posterior  branch  of 
the  spiral  nerve :  the  biceps  tendon  passes  through 
the  fibres  of  the  muscle  where  they  cover  the  tuber- 


MUSCLES  OF  FORE-ARM.  49 

lie  of  the  radius.     The  use  of  these  muscles  is  indi- 
cated by  their  names. 

Muscles  on  the  back  of  the  Fore-Arm. 
Superficial  set,  4. 

Extensor  digitorum  communis,  Or.  1,  by  a  tendon, 
which  it  shares  with  the  ext.  carp.  r.  b.,  ext.  carp, 
uln.,  and  ext.  min.  digit.,  from  the  ext  condyle;  2, 
from  the  intermuscular  aponeuroses.  Ins.  into  the 
phalanges  by  four  tendons,  each  of  which  first  sends 
off  an  expansion  from  its  edges  to  cover  the  dorsum 
of  the  first  phalanx,  and  then,  dividing  into  three  slips 
sends  one  to  the  upper  end  of  the  second  phalanx,  and 
one  on  each  side  of  the  first  joint  to  the  upper  end  of 
the  last  phalanx ;  the  three  ext.  tendons  are  united  by 
transverse  slips,  before  they  reach  the  phalanges. 

Extensor  minimi  digiti,  Or.  from  the  outer  condyle 
by  the  common  tendon ;  Ins.  back  part  of  the  phalan- 
ges of  the  little  finger,  like  the  corresponding  tendon 
of  the  common  extensor. 

Extensor  carpi ulnaris,  Or.  1,  outer  condyle  by  the 
common  tendon;  2,  post,  surface  and  outer  edge  of 
the  ulna ;  Ins.  back  part  of  the  carpal  end  of  the  fifth 
metacarpal  bone.  The  uses  of  the  preceding  mus- 
cles are  indicated  by  their  names. 

Anconseus,  Or.  by  a  distinct  tendon  from  the  miter 
condyle ;  Ins.  1,  into  the  outside  of  the  olecranon 
where  it  is  continuous  with  the  triceps ;  2,  triangular 
surface  on  the  upper  fourth  of  the  ulna.  Use,  to 
extend  the  fore-arm. 

Deep-set,  4. 

Extensor  metacarpi  pollicis,  Or.  from  the  ulna,  in- 
terosseous  ligament,  and  radius,  just  below  the  su- 
pin.  brevis  muscle;  Ins.  back  part  of  the  carpal  end 
of  the  first  metacarpal  bone. 
5 


50  ARTERIES  OF  FORE-ARM. 

Extensor  primii  nternodii,  Or.  1,  radius  and  inte- 
rosseous  ligament  below  the  last  m.;  2,  slightly  from 
the  ulna.  Ins.  back  part  of  the  carpal  end  on  the 
first  phalanx. 

Extensor  secundi  internodii,  Or.  broad  from  the  mid- 
dle third  of  the  back  of  the  ulna,  and  slightly  from 
the  interosseous  ligament.  Ins.  back  of  the  carpal 
end  of  the  second  phalanx.  The  use  of  the  prece- 
ding muscles  is  indicated  by  their  names. 

Indicator,  ?)/\Jgfick  part  of  the  ulna  and  interros- 
seous  ligamentTbeLow  the  la^t  muscle;  Ins.  by  slips 
into  the  phalanges  of  the  index  finger,  like  the 
common  ext.  -ff^p^tD^extend  the  forefinger,  as  in 
pointing.  ~__  ^~  -^" 

In  the  dissection-eftliG-muFcles  of  the  fore-arm,  the 
vessels  and  nerves  of  this  region  are  exposed.  The 
arteries  are  the  radial,  ulnar,  and  interosseous. 

The  radial  artery  proceeds  from  the  bifurcation  of 
the  brachial  art.  opposite  the  coronoid  process  of  the 
ulna,  along  the  outer  and  ant.  surface  of  the  fore- 
arm, at  first  deep  but  inferiorly  superficial,  and  then 
winds  around  the*  ext.  lat.  lig.  of  the  wrist  to  pass 
between  the  first  and  second  metacarpal  bones  into 
the  palm  of  the  hand.  Its  principal 'branches  are  the 
radial  recurrent,  and  superficialis  volae  ;  the  rest  are 
muscular  branches. 

The  ulnar  art.  lies  on  the  inner  and  ant.  surface  of 
the  fore-arm,  and  like  the  preceding,  becomes  more 
superficial  near  the  wrist;  it  here  passes  above  the 
annular  lig.  and  enters  the  palm  of  the  hand.  Its 
principal  branches  are  the  ant.  andpost.  ulnar, recur- 
rent anfl  interosseous;  the  rest  are  chiefly  muscular. 
~*  The  inferosse&HS  art.  is  a  branch  of  the  ulnar;  it 
sinks  deep,  lies  on  the  interosseous  membrane,  and 
terminates  in  the  pronator  quadratus  muscle.  Its 
principal  branch  is  the  post,  interosseous,  which 
passes  to  the  back  of  the  fore-arm  between  the  ant. 
oblique  lig.  and  the  interosseous  membrane. 


THE    HAND.  51 

The  nerves  met  with  in  the  fore-arm  are  the  muscu- 
lo-spiral,  or  radial,  ulnar  and  median. 

The  mu sculo- spiral,  or  radial  nerve,  joins  the  radial 
at  the  junction  of  the  upper  and  middle  thirds  of  the 
fore-arm,  runs  along  its  outer  side,  and  at  the  junc- 
tion of  the  middle  and  lower  thirds  winds  around  the 
radius  beneath  the  supinator  longus  tendon  to  the 
back  of  the  wrist  and  hand;  a  little  beneath  the  elbow 
it  sends  off  its  largest  branch,  which  perforates  the 
supinator  brevis  to  supply  the  muscles  on  the  back  of 
the  fore-arm. 

The  ulnar  nerve  accompanies  the  ulnar  art.  on  its 
inner  side,  and  enters  with  it  the  palm  of  the  hand ; 
its  principal  branch  proceeds  from  it  some  distance 
above  the  wrist,  and  bends  round  the  ulna  to  the  back 
of  the  wrist  and  hand. 

The  median  nerve  accompanies  the  brachial  art., 
sinking  into  the  fossa  beneath  the  elbow,  passes  be- 
tween the  two  heads  of  the  pronator  quadratus,  de- 
scends to  the  wrist,  where  it  lies  behind  the  palmaris 
longus  tendon,  and  enters  the  palm  of  the  hand,  be- 
neath the  annular  lig. 

The  deep-seated  veins  are  the  venae  comites,  two  of 
which  accompany  each  art.,  lying  on  either  side; 
they  unite  generally  at  the  elbow  to  form  the  brachial 
vein,  although  the  basilic  frequently  joins  the  rest 
above  the  joint. 

SECTION    V. 
Of  the  Hand. 

Beneath  the  integuments  of  the  palm  of  the  hand 
and  a  quantity  of  adipose  tissue,  lies  the  palmar  apo- 
neurosis,  or  fascia.  This  is  exceedingly  dense;  trian- 
gular in  shape,  it  proceeds  posteriorly  from  the  ant. 
annular  lig.  forwards  and  divides  into  four  fasciculi, 
each  of  which  subdivides  into  two,  to  allow  of  the 
passage  of  the  flexor  digitorum  tendons,  the  digital 


52  MUSCLES    OF    THE    HAND. 

vessels  and  nerves,  and  pass  to  be  inserted  into  the 
lateral  ligaments  of  the  metacarpo-phalangeal  articu- 
lations. 

Beneath  this  lie  the  muscles,  vessels,  and  nerves, 
with  the  exception  of  the  palmar  brevis,  which  lies 
superficial  to  it. 

Muscles  of  the  hand,  19. 
Those  on  the  outer  edge,  4. 

Abductor pollicis,  Or.  from  the  scaphoid  bone  and 
annular  ligament  of  the  carpus;  Lis.  with  the  outer 
head  of  the  short  flexor. 

Opponens pollicis,  Or.  from  the  trapezium  and  an- 
nular ligament:  Ins.  whole  length  of  the  outer  edge 
of  the  metacarpal  bone. 

Flexor  brevis  pollicis,  Or.  by  two. portions,  1,  from 
the  trapezium,  lower  edge  of  the  annular  ligament, 
and  sheath  on  the  flex,  carp,  rad.  m. ;  2,  from  the  os 
magnum.  Ins.  by  two  heads,  each  enclosing  a  sesa- 
moid  bone,  into  both  sides  of  the  first  phalanx,  with 
abductor  on  one  side,  and  the  abductor  m.  on  the 
other. 

Abductor  pollicis,  Or.  the  whole  length  of  the  ant. 
surface  of  the  third  metacarpal  bone;  Ins.  with  the  in- 
ner head  of  the  short  flexor.  The  use  of  these  mus- 
cles is  indicated  by  their  name. 

Muscles  on  the  inner  edge,  4. 

Palmaris  brevis,  quadrilateral  Or.  annular  ligament 
and  inner  edge  of  the  palmar  fascia  ;  Ins.,  its  short 
parallel  fibres  are  lost  in  the  skin  over  the  inner  edge 
of  the  hand.  Use,  to  corrugate  the  integ.,  on  the  in- 
ner side  of  the  hand. 

Abductor  minimi  digiti,  Or.  pisiform  bone;  I/is,  in- 
ner edge  of  the  base  of  the  first  phalanx. 

Flexor  brevis,  d.  minimi,  thin  when  it  exists,  Or. 
lower  edge  of  the  carpal  annular  lig.  and  unciform 


RELATIONS.  53 

process  is  soon  identified  with  the  former.    The  ulnar 
art.  and  nerve  separate  them  at  their  origins. 

Opponens  dig.  minimi,  Or.  the  same  as  the  short 
flexor;  Ins.  whole  length  of  the  inner  edge  of  the  fifth 
metacarpal  bone.  The  use  of  these  muscles  is  indi- 
cated by  their  names. 

Muscles  in  the  middle  of  the  Hand,  11. 

Lumbricales,  Or.  fore  and  outer  parts  of  each  ten- 
don of  the  flexor  profundus;  Ins.  with  the  correspond- 
ing interossei  into  the  edge  of  the  dorsal  expansion  on 
the  same  side.  Use,  to  assist  the  flexor  tendons,  or 
to  act  with  them. 

The  interossei.  If  the  median  line  or  axis  of  the 
third  metacarpal  bone  be  taken  as  a  fixed  point,  the 
palmar  int  erossei  may  be  considered  as  adductors,  and 
the  dorsal  as  abductors  ,  both  sets  arise  from  the  op- 
posite edges  of  two  metacarpal  bones  and  are  inserted 
into  the  edges  of  the  dorsal  expansion.  The  dorsal 
interossei,  four  in  no.,  are  attached,  the  first,  or  indi- 
cator, to  the  radial  edge  of  the  index  finger,  the  se- 
cond, to  the  radial  edge  of  the  medius,  the  third  to 
the  ulnar  edge  of  the  medius,  and  the  fourth,  to  the 
ulnar  edge  of  the  ring  finger.  The  palmar  interossei, 
three  in  no.,  are  attached,  the  first,  to  the  ulnar  edge 
of  the  index,  the  second,  to  the  radial  edge  of  the  ring 
finger,  and  the  third,  to  the  radial  edge  of  the  little 
finger. 

The  relations  of  the  parts  about  the  wrist-joint  are 
as  follows.  A.  Back  of  the  joint,  1,  styloid  process  of 
the  radius  and  ins.  of  the  supinator  longus,  covered  by 
the  tendons  of  ext.  metacarpiet  primiinternodiipol- 
licis;  2,  the  tendon  of  the  ext.  secund.  internodii.  In 
their  triangular  interval  between  this  m.  and  the  two 
latter,  may  be  felt  the  radial  artery  just  before  it 
passes  between  the  metacarpal  bones,  and  the  tendons 
of  the  two  radial;  extensors;  3,  the  tendon  of  the  ex- 
ten,  indicis,  those  of  the  common  extensor,  and  that 
5* 


54         VESSELS    AND    NERVES    OF    HAND. 

of  the  exten.  min.  digit! ;  4,  the  extensor  carpi  ulna- 
ris,  and  thestyloid  process  of  the  ulna.  B.  Forepart 
of  the  joint,  commencing  at  the  same  point,  1,  surface 
of  the  radius,  supporting  the  radial  artery ;  2,  tendon 
of  the  flexor  carpi  radialis,  and  immediately  beneath 
it  that  of  the  flexor  proprius  pollicis;  8,  tendon  of  the 
palmaris  longus,  the  tendon  of  the  flexor  profundus 
being  felt  in  the  interval ;  4,  flexor  carpi  ulnaris  and 
pisiform  bone,  the  tendons  of  the  flexor  sublimis  sup- 
porting the  ulnar  artery  and  nerve  in  the  interval. 
The  median  nerve  passes  under  the  annular  ligament, 
imbedded  in  the  flexor  tendons,  and  at  the  ulnar  edge 
of  the  flexor  c.  radialis. 

The  arteries  and  nerves  me\  within  the  palm  of  the 
hand  are  the  superficial  and  deep  palmar  arches. 

The  superficial  palmar  arch  of  arteries  lies  immedi- 
ately beneath  the  palmar  aponeurosis;  it  is  formed  by 
the  ulnar  art.  and  superficialis  voloe  branch  of  the  ra-* 
dial,  and  supplies  three  and  a  half  fingers,  counting 
from  the  little  finger. 

The  superficial  palmar  arch  of  nerves  accompanies  ' 
this,  lying  beneath  it ;  this  is  formed  by  the  median 
nerve,  and  supplies  three  and  a  half  fingers,  counting 
from  the  thumb,  the  remaining  finger  and  a  half  being 
supplied  by  the  ulnar  nerve. 

The  deep  palmar  arch  of  arteries  and  nerves  lies  be- 
neath the  flexor  tendons  on  the  interossei  muscles;  the 
first  is  formed  by  radial  art.  with  the  deep  branch 
of  the  ulnar  ;  it  supplies  one  finger  and  a  half  count- 
ing from  the  thumb ;  the  latter  is  formed  by  the  deep 
branch  of  the  ulnar,  and  is  lost  chiefly  in  the  interossei 
muscles. 


55 


CHAPTER  IV. 

THE    TRUNK 

is  composed  of  two  large  cavities,  the  thorax  and  ab- 
domen, each  of  which  contains  important  viscera,  most 
of  these  belonging  to  the  organic  life  of  the  individual. 
The  pelvis  assists  in  forming  the  trunk  inferiorly.  It 
will  be  described  with  the  lower  extremities. 

SECTION  1. 
The  Thorax 

is  a  large  conical  cavity  giving  lodgment  to  and  pro- 
tecting the  great  central  organs  of  respiration  and  cir- 
culation, namely,  the  lungs,  heart,  aorta,  pulmonary 
artery,  vena  cava,  thoractic  duct,  &c.  It  is  formed  by 
the  twelve  dorsal  or  thoracic  vertebras  posteriorly;  the 
ribs  posteriorly,  laterally,  and  in  front;  the  sternum 
and  costal  cartilages  anteriorly ;  its  apex  is  truncated, 
and  forms  an  oval  aperture  superiorly,  bounded  by 
the  first  dorsal  vertebra  posteriorly,  the  first  rib  la- 
terally, and  the  upper  end  of  the  sternum  and  first 
costal  cartilage  in  front ;  through  this  pass  upwards 
the  sternohyoid.  sterno  thyroid,  andlonguscolli  mus- 
cles; the  arteria  innominata,  left  subclavian,  and  ca- 
rotid arteries ;  cone  of  the  pleura,  right  and  left  re- 
current nerves,  and  thoracic  duct ;  downwards,  the 
vense  innominates,  internal  mammary,  and  superior  in- 
tercostal arteries;  pneumogastric,  phrenic,  recurrent 
and  sympathetic  nerves,  trachea,  and  oesophagus. 

The  base  of  the  thorax  is  formed  inferiorly  by  the  dia- 
phragm; through  this  pass  the  aorta,  inferior  vena 
cava,  and  venaazygos,  pneumogastric,  phrenic,  splan- 
chnic, and  sympathetic  nerves,  oesophagus  and  tho- 
racic duct.  The  perpendicular  diameter  is  greatest 
posteriorly  and  laterally,  least  anteriorly;  the  trans- 


56  ANTERIOR    MEDIASTINUM. 

verse  is  greatest  inferiorly,  least  superiorly;  the  antero 
posterior  is  greatest  inferiorly  from  the  lower  end  of 
the  sternum  backwards  to  the  spine. 

The  THORACIC  CAVITY  is  divided  into  five  compart- 
ments by  the  reflexion  of  the  pleura,  of  these  two  are 
on  the  mesial  lines,  the  anterior  and  posterior  medi- 
astinum; one,  on  the  left  side,  the  pericardium,  and 
two  laterally  the  pleura  cavities  for  the  lungs. 

Thepleura  is  a  serous  membrane  which  lines  most 
of  the  interior  of  the  thorax,  one  on  each  side,  each 
being  distinct  from  the  other,  so  as  to  form  two  sepa- 
rate membranes.  The  right  is  the  larger  but  shorter. 

Each  pleura  passes  upwards  into  the  neck  as  high 
as  the  fourth  cervical  vertebra,  forming  its  cone ;  in- 
feriorly it  lines  the  upper  surface  of  the  diaphragm, 
and  here  forms  the  ligamentum  latum  pulmonis ;  in- 
termediately it  is  reflected  in  the  following  manner; 
from  about  the  junction  of  the  sternum  and  costal  car- 
tilages it  passes  outward,  lining  the  inner  surface  of 
the  ribs,  until  it  reaches  to  the  side  of  the  dorsal  ver- 
tebra; it  here  turns  forward,  forming  the  side  of  the 
posterior  mediastinum,  and  passes  outwards  on  the 
post,  surface  of  the  root  of  the  lungs,  lines  these  or- 
gans, passing  in  between  their  lobes,  round  the  ant. 
surface  of  the  root  of  the  lungs,  then  lines  the  lateral 
surface  of  the  pericardium,  from  which  it  approaches 
its  fellow  of  the  opposite  side,  passes  forwards  and 
outwards,  forms  the  lateral  boundary  of  the  anterior 
mediastinum,  and  arrives  at  the  junction  of  the  ster- 
num and  costal  cartilages.  The  pleura  is  divided  as 
it  lines  the  lungs  or  ribs  into  the  pleura  pulmonalis 
and  costalis;  the  latter  is  the  stronger  of  the  two* 

The  anterior  mediastinum  inclines  downwards  and  a 
little  to  the  left  side ;  it  extends  from  the  upper  to  the 
lower  extremity  of  the  sternum,  triangular  in  shape, 
its  base  turned  forwards  is  formed  by  the  post,  sur- 
face of  the  sternum  and  a  little  by  the  costal  cartilages, 
its  apex  turned  backwards  is  formed  by  the  conver- 


STRUCTURE    OF    LUNGS.  57 

gence  of  the  pleura},  which  bound  it  laterally;  it  is 
slightly  contracted  in  the  centre.  Its  contents  are  the 
thymus  gland,  the  triangularis  sterni  muscles,  and 
the  int.  mammary  arteries. 

The  thymus  gland  is  largest  in  the  foetus,  when  it 
nearly  fills  the  ant.  mediastinum;  it  consists  of  two 
lobes,  divided  by  an  oblique  fissure.  Its  use  is  wholly 
unknown.  In  the  adult  it  degenerates  into  cellular 
tissue. 

The  lungs  are  the  great  organs  of  respiration.  Each 
lung  is  conical  in  shape,  and  corresponds  to  the  pleu- 
ral  cavity ;  the  apex  fits  into  the  cone  of  the  pleura  ; 
its  base,  concave,  rests  on  the  upper  surface  of  the 
diaphragm;  its  anterior  surface,  concave,  is  applied 
against  the  pericardium;  the  outer  and  posterior  sur- 
faces are  convex.  The  right  lung  is  the  larger  but 
shorter,  and  consists  of  three  lobes;  the  left  has  but 
two  lobes.  These  lobes  are  separated  by  the  great  fis- 
sure which  runs  obliquely  downwards  and  forwards, 
so  as  to  divide  each  lung  into  an  interior  smaller,  and 
a  post,  larger  lobe;  from  the  middle  of  the  fissure  pro- 
ceeds a  small  fissure  on  the  right  side,  cutting  oif  the 
third  from  the  superior  lobe. 

The  root  of  the  lung  is  formed  by  an  assemblage  of 
the  several  structures  entering  or  leaving  the  organ — 
viz.,  the  bronichial  tube,  pulmonary  art.,  and  pulmo- 
nary veins,  surrounded  by  cellular  tissue,  and  covered 
by  the  pleura.  The  order  of  parts  in  each  lungis  from 
behind  forwards,  bronchus,  artery,  veins;  from  above 
downwards,  on  the  right  side,  bronchus,  art.,  veins: 
on  the  left,  art.,  bronchus,  veins;  these  are  enveloped 
by  the  pulmonic  plexus  of  nerves,  best  marked  on  the 
posterior  surface,  and  formed  by  the  pneumogastric 
and  sympathetic  nerves .  A  number  of  dark-coloured 
glands,  bronchial  glands,  are  found  around  the  root  of 
each  lung. 

The  structure  of  the  lungs  is  composed  of  bronchial 
tubes  and  air  cells,  pulmonary  arteries  and  veins  united 
by  fine  areolar  tissue, 

I 


58  PULMONARY   PLEXUS. 

The  bronchial  tubes  are  the  continuation  of  the 
trachea,  from  the  bifurcation  of  which,  opposite  the 
second  dorsal  vertebra,  they  descend  obliquely  down- 
wards and  outwards  to  the  root  of  each  lung.  The 
right  bronchus  is  less  oblique  than  the  left;  it  passes 
behind  the  superior  cava  to  the  root  of  the  lung;  the 
left  bronchus  passes  through  the  arch  of  the  aorta,  in 
front  of  the  thoracic  aorta,  to  the  root  of  its  lung. 
The  bronchial  tubes  divide  into  numerous  branches, 
which  ultimately  terminate  in  forming  the  air  cells, 
which  form  a  slight  expansion  resembling  a  cluster  of 
grapes.  A  bunch  or  cluster  of  the  air  cells  form  the 
lobules,  and  these  united  form  the  lobes.  These  lo- 
bules are  united  by  fine  areolar  tissue,  the  interlobular 
cellular  tissue,  in  which  the  pulmonary  arteries  and 
veins  run  to  their  destination. 

The  structure  of  the  bronchial  tubes  is  the  same  as 
that  of  the  trachea,  except  in  their  small  branches  and 
air  cells,  which  want  the  cartilaginous  structure.  The 
structures  of  these  consist  of  an  internal  lining  mu- 
cous membrane,  an  ext.  cellular  coat,  and  a  thin  layer 
of  muscular  fibres  between:  some  deny  the  existence 
of  these. 

The  pulmonary  arteries  enter  the  lungs  at  their  root, 
and  divide  the  right  into  three,  the  left  into  two 
branches,  to  supply  the  lobes ;  they  gradually  break 
down  into  capillary  vessels,  which  ramify  on  the  outer 
surface  of  the  air  cells,  and  so  conduct  the  black  blood 
to  be  oxygenated  by  the  atmospheric  air. 

The  pulmonary  veins  arise  from  the  capillaries  of  the 
pulm.  art.,  and  unite  on  each  side  into  two  large  ves- 
sels, which  cross  inwards,  and  open  into  the  posterior 
surface  of  the  left  auricle  of  the  heart;  and  thus  con- 
duct the  art.  blood  info  this  organ.  The  right  are 
longer  and  larger  than  the  left. 

The  pulmonic  plexus  sends  its  numerous  filaments 
along  the  posterior  surface  of  the  bronchial  tubes  to 
their  minutest  ramifications,  and  finally  terminates  in 
the  air  cells. 


THE    TRACHEA.  59 

The  absorbents  of  the  lungs  are  numerous,  and  ter- 
minate in  the  bronchial  glands. 

The  bronchial  arteries  are  small  vessels  which  arise 
from  the  thoracic  aorta  to  supply  the  lungs  with  nu- 
trition. Their  blood  is  returned  by  the  bronchial 
veins.  There  is  a  free  anastomosis  between  them  and 
the  pulmonary  vessels. 

The  lungs  in  the  healthy  adult  are  of  a  mottled 
gray  colour,  are  light  and  spongy ;  in  the  young  sub- 
ject, after  breathing,  they  are  of  a  reddish  colour,  be- 
fore breathing  are  dark  red;  in  the  diseased  state 
they  are  frequently  nearly  black,  from  a  deposit  of 
carbon  in  their  structure. 

The  lungs  are  light  and  spongy,  and  float  in  water. 

The  trachea  descends  from  the  termination  of  the 
larynx,  opposite  about  the  fourth  cervical  vertebra, 
downwards  and  a  little  to  the  right  side  of  the  mesial 
line  of  the  neck,  enters  the  cavity  of  the  thorax  be- 
tween the  ant.  and  post,  mediastinum,  and  divides 
opposite  the  second  dorsal  vertebra  into  the  right  and 
left  bronchial  tubes. 

In  the  neck,  the  trachea  is  covered  in  front  by  the 
sterno  hyoid  and  thyroid  muscles,  and  partly  by  the 
thyroid  gland ;  it  rests  posteriorly  on  the  oesophagus, 
which  inclines  to  its  left  side;  on  each  side  of  it  is  the 
carotid  sheath  and  contents,  the  recurrent  and  sym- 
pathetic nerves.  In  the  thorax  it  is  crossed  by  the 
thymus  gland,  and  left  vena  innominata,  and  sup- 
ports the  upper  part  of  the  arch  of  the  aorta.  The 
phrenic,  pneumogastric,  and  sympathetic  nerves  de- 
scend to  its  outer  side,  and  behind  it  is  the  oesophagus 
and  spinal  column.  The -right  vena  innominata  de- 
scends on  its  right  side,  the  thoracic  duct  ascends  on 
its  left  side,  but  post,  to  it. 

The  structures  of  the  trachea  consist  of  cartilaginous 
rings,  fibrous  tissue,  mucous  membrane,  and  muscu- 
lar fibres.  The  tracheal  rings  form  but  three  parts 
of -a  circle,  being  deficient  posteriorly.  They  are  from 


60  VENA   AZYGOS. 

eighteen  to  twenty  in  number,  and  vary  in  size ;  the 
first  is  the  largest ;  they  are  connected  by  fibrous  mem- 
brane. The  trachea  is  completed  posteriorly,  where 
the  rings  are  deficient,  by  three  layers  of  tissue,  the 
ext.  isfibrous,  some  consider  elastic;  the  next  is  trans- 
verse muscular  fibre:  and  the  internal  is  the  lining 
mucous  membrane ;  between  these  are  some  small 
glands  which  open  on  the  mucous  membrane. 

The  pericardium  and  heart  occupy  the  middle  me- 
diastinum, and  will  be  found  under  the  head  of  the 
Vascular  System. 

The  posterior  mediastinum  extends  nearly  on  the  me- 
sial line  in  front  of  the  spine,  from  the  second  or  third 
to  the  tenth  dorsal  vertebra,  triangular  in  shape,  its 
apex,  turned  forwards,  is  formed  by  the  convergence 
of  the  pleurae,  its  base  backwards  by  the  spinal  co- 
lumn; its  contents  are,  the  oesophagus  and  thoracic 
aorta  to  the  left  side,  the  vena  azygos  to  the  right, 
the  thoracic  duct  in  the  centre,  the  splanchnic  nerves 
are  found  in  its  lower  part. 

The  oesophagus  descends  from  the  pharynx  to  the 
left  side  behind  the  trachea,  through  the  arch  of  the 
aorta,  crosses  a  little  in  front  of  the  thoracic  aorta, 
perforates  the  diaphragm,  and  terminates  in  the  car- 
diac extremity  of  the  stomach:  on  its  surfaces  are 
found,  a  little  above  the  diaphragm,  the  pneumogas- 
tric  nerves,  the  left  being  anterior.  The  oesophagus 
is  composed  of  longitudinal  muscular  fibres,  lined  by 
mucous  membrane ;  some  circular  fibres  are  described 
at  its  cardiac  extremity,  but  their  existence  in  the 
human  subject  may  well  be  questioned. 

The  thoracic  aorta  lies  to  the  left  side  of  the  spine, 
but  inferiorly  comes  forward  in  front,  and  enters  the 
abdomen  through  the  aortic  opening. 

The  vena  azygos  is  formed  by  the  junction  of  the 
lumbar  veins  in  front  of  the  second  lumbar  vertebra ;  it 
ascends  through  the  aortic  opening  of  the  diaphragm, 
passes  upwards  in  the  posterior  mediast,  to  its  right 


THORACIC    DUCT.  6T 

side,  and  finally  hooking  round  the  root  of  the  right 
lung,  terminates  in  the  sup.  vena  cava:  in  this  course 
it  receives  the  eight  or  nine  inferior  intercostal  veins, 
and  generally  the  left  vena  azygos,  which  crosses  from 
the  left  side  behind  the  aorta  to  join  it;  this  is  formed 
by  the  six  inf.  intercostal  veins  of  the  left  side ;  the 
remaining  intercostal  veins  form  the  superior  inter- 
costal veins,  and  terminate  in  the  right  vena  inno- 
minata ;  the  left  receives  the  superior  six  intercostal 
veins  on  its  side,  and  terminates  in  the  left  vena  inno- 
minata. 

The  thoracic  duct  is  the  trunk  of  the  absorbent  sys- 
tem ;  it  is  formed  in  front  of  the  third  lumbar  vertebra 
by  the  junctions  of  the  lymphatics  from  the  lower  ex- 
tremities and  pelvis,  and  passes  upwards  in  front  of 
the  spine;  it  escapes  from  the  abdomen  through  the 
aortic  opening  of  the  diaphragm,  between  the  aorta  to 
its  left  and  the  vena  azygos  to  its  right  side,  enters  the 
post,  mediastinum,  ascends  on  the  mesial  line  of  the 
spine,  inclines  to  its  left  side,  passes  behind  the  arch 
of  the  aorta,  and  ascends  into  the  neck,  behind  the  left 
carotid  and  int.  jugular  vein,  as  high  as  the  sixth  cer- 
vical vertebra ;  it  now  turns  downwards  and  inwards, 
and  terminates  in  the  left  subclavian  vein  near  its 
junction  with  the  int.  jugular. 

In  its  course  the  thoracic  duct  occasionally  divides 
into  two  or  more  branches,  which  unite  again  into  one 
trunk.  Its  structure  consists  of  two  coats,  an  exter- 
nal fibrous  and  an  internal  serous,  which  is  thrown 
into  numerous  folds  forming  valves. 

There  is  generally  a  small  thoracic  duct  on  the  right 
side,  which  conveys  the  absorbents  from  the  right  side 
of  the  head  and  neck  and  right  arm  into  the  right  sub- 
clavian vein. 

The  splanchnic  nerves  are  formed  from  the  last  six 
dorsal  ganglia  of  the  sympathetic ;  they  perforate  the 
diaphragm,  and  terminate  in  the  semilunar  ganglion 
and  renal  plexus. 
6 


62  THE   ABDOMEX. 

SECTION  II. 
The  Abdomen, 

the  largest  cavity  in  the  human  body,  is  bounded 
above  by  the  diaphragm,  below  by  the  pelvis,  behind 
by  the  lumbar  vertebrae  and  quadratus  lumborum  mus- 
cles, laterally  and  in  front  by  the  abdominal  muscles. 
Unlike  the  thorax,  its  parietes  are  chiefly  muscular, 
and  thus  exert  a  necessary  pressure  on  the  abdominal 
viscera. 

The  abdomen  is  divided,  for  the  purposes  of  descrip- 
tion, into  three  principal  regions,  namely,  the  upper 
or  epigastric,  the  central  or  umbilical,  and  the  inferior 
or  hypogastric.  A  line  drawn  from  the  inferior  edge 
of  the  costal  cartilages  across  to  the  opposite  side  se- 
parates the  two  superior,  and  a  similar  transverse 
line  drawn  between  the  ant.  sup.  spinous  processes  of 
the  illium  separates  the  two  inferior;  each  of  these 
regions  is  further  subdivided  into  three  by  thelineae 
semilunares,  which  extend  from  the  cartilages  of  the 
eighth  or  ninth  rib  down  wards  and  inwards  towards 
the  pubis. 

The  epigastric  thus  consists  of  a  central,  or  epiga^- 
tric  region,  and  a  right  and  left  hypochondriac;  the 
umbilical  of  a  central  umbilical  and  a  right  and  left 
lumbar ;  and  the  hypogastric  of  a  central  hypogastric 
and  a  right  and  left  iliac  region.  The  lower  portion 
of  this  region  is  further  subdivided  into  a  central  pubio 
and  a  right  and  left  inguinal  region. 

Anterior  and  Lateral  Muscles  of  the  Abdomen,  5. 

Obliquus  externus,  Or.  the  eighth  or  ninth  infer,  ribs 
by  fleshy  digitations,  of  which  five  intersect  with  the 
serratus  magnus,  and  three  or  four  with  the  latissi- 
mus  dorsi;  Ins.,  1,  fleshy  into  the  ant.  two-thirds  of 
the  crista  ilii ;  2,  the  rest  of  the  muscle  ends  at  a  line 
from  the  ant.  sup.  spinous  p.  to  the  ensiform  cartilage 


MUSCLES    OF   THE  ABDOMEN  63 

in  an  aponeurosis,  by  which  it  is  ins.  into  the  wiiole 
length  of  the  linea  alba,  the  lower  portion  c  ithis 
aponeurosis  (Poupart  ligament)  extends  from  the 
ant.  sup.  spin.  p.  across  the  femoral  vessels  to  be  ins. 
by  one  slip  (int.  pillar  of  the  ext.  ring)  into  the  sym- 
physis  pubis,  by  another  (ext.  pillar  of  the  ext.  ring) 
into  the  spine  of  the  pubis;  3,  by  a  broader  portion 
(  Gimbernat's ligament,)  which  is  folded  under  the  cord, 
presenting  a  sharp  lunated  edge  towards  the  femoral 
vessels,  into  the  spine  of  the  pubis,  and  an  inch  along 
the  pectineal  line  .•.  tht  reflected  portion  of  the  apo- 
neurosis forms  the  ant.  and  inf.  walls  of  the  inguinal 
canal  .-.  a  space  exists  between  its  post,  edge  and  the 
ant.  edge  of  the  latis.  dorsi  m.  which  has  been  the 
seat  of  hernial  protrusion,  (Petit.)  Use,  to  depress 
the  ribs  and  compress  the  abdominal  viscera,  to  raise 
the  pelvis  if  the  thorax  be  fixed,  or  to  depress  them 
forwards  if  the  pelvis  be  fixed. 

Obliquus  internus,  Or.  1,  from  the  fascia  lumborum ; 
2,  ant.  two-thirds  of  the  crista  ilii ;  3,  from  the  ext. 
two-thirds  of  the  grooved  or  internal  surface  of  Pou- 
part's  ligament.  Ins.  the  upper  portion,  fleshy  into 
the  edges  of  the  four  inf.  costal  cartilages;  the  middle 
terminates  at  the  linea  semilunaris  in  the  middle  ab- 
dominal aponeurosis,  by  which  it  is  continued  to  the 
linea  alba ;  the  portion  from  Poupart' s  ligament  (with 
the  lower  fibres  of  the  transversalis)  arches  over,  and 
then  behind,  the  cord  (Cooper,)  to  be  ins.  4nto  the 
body  of  the  pubis,  behind  the  ext.  ring,  and  into  the 
pectineal  line  .  •.  the  last  portion,  with  the  transver- 
salis, forms  the  upper  and  posterior  walls  of  the  ing. 
canal.  (Fascise.)  Use,  nearly  similar  to  the  preceding; 
it  rotates  the  trunk  in  the  opposite  direction,  and 
thus  co-operates  with  the  ext.  obliquus  of  the  other 
side  of  the  body. 

Cremaster,  Attachments,  1,  ext.  two-thirds  of  Pou- 
part1 s  ligament;  2,  behind  that  ligament  at  its  pubic 
attachment ;  the  intervening  fibres  descend  in  succes- 


64  MUSCLES    OF    ABDOMEN. 

sive  loops  to  be  ins.  into  the  cord,  and  to  surround 
the  tunica  vaginalis,  so  as  to  sling  the  testicle  .•.  the 
testicle,  in  its  passage  beneath  the  lower  edge  of  the 
obliquus  int.  m.,  draws  down  with  it  the  muscular 
fibres  to  form  the  cremaster  (Cloquet ; )  the  cord  passes 
between  the  lower  fibres  of  the  transversalis,  from 
which  also  the  muscle  is  derived.  (Guthrie.)  Use,  to 
suspend  the  testis. 

Transversalis,  Or.  1,  ext.  two-thirds  of  Poupart's 
ligament;  2,  ant.  three-fourths  of  the  crista  ilii;  3, 
fascia  lumborum  ;  4,  inner  surfaces  of  the  six  lastribs, 
by  digitations,  which  intersect  with  the  diaphragm. — 
Ins.  the  upper  part  terminates  at  the  linea  semiluna- 
ris  in  the  post,  aponeurosis,  by  which  it  is  continued 
to  the  linea  alba :  that  from  Poupart's  ligament  passes 
over  and  behind  the  chord  to  be  ins.  with  the  int. 
obliq.  into  the  pubic  end  of  Poupart's  ligament  and 
ilio  pectineal  line.  Another  portion  passes  behind 
and  then  under  the  cord,  in  front  of  the  fascia  trans- 
versalis, to  Poupart's  ligament;  thus  forming  the 
poster,  and  part  of  the  inf.  wall  of  the  inguinal  canal. 
(Cooper.)  Use,  to  assist  the  obliq.  muscles  in  respi- 
ration and  the  compression  of  abdm.  viscera. 

Rectus  Abdominis,  Or.  by  a  double  tendon  from  the 
pubis,  between  its  spine  and  symphysis;  is  ins.  by 
three  portions:  1,  ensiform  cartilage  and  costo  xiphoid 
lig.:  2,  fifth  costal  cartilage;  3,  sixth  and  seventh 
costal  cartilages  .-.  The  muscular  fibres  are  partially 
interrupted  by  three  or  four  zigzag  tendinous  inter- 
sections which  adhere  to  the  forepart  of  the  sheath. 
Use,  to  approximate  the  pelvis  and  thorax. 

Pyramidalis,  triangular,  sometimes  absent,  Or.  by 
its  base,  from  the  pubis  and  ant.  pubic  ligament.  Ins. 
by  its  apex  into  the  linea  alba,  sometimes  as  high  as 
half-way  towards  the  umbilicus.  Use,  to  assist  the 
preceding. 

These  muscles  are  enclosed  in  a  fibrous  sheath, 
formed  by  the  tendons  of  the  obliquus  and  transver- 


THE   DIAPHRAGM.  65 

sails  muscles.  This  sheath  extends  from  the  xiphoid 
and  costal  cartilages  superiorly,  to  the  crest  of  the 
pubis,  into  which  it  is  implanted;  it  is  formed  by  the 
ext.  oblique  tendon,  and  one  layer  of  the  int.  oblique 
passing  in  front  of  the  rectus  muse,  and  behind  by 
the  second  layer  of  the  int.  obliquus  and  transversalis, 
except  from  half- way  between  the  umbilicus  and  pubis 
to  this  bone,  where  the  whole  of  the  tendons  pass  in 
front  of  the  rectus;  this  muscle  is  intersected  by  three 
or  four  irregular  transverse  lines:  the  lineoe  trans- 
versse  one  at  the  umbilicus,  one  at  the  xiphoid  carti- 
lage, one  between  these,  and  one  sometimes  beneath 
the  umbilicus.  By  this  intersection  each  portion  of 
the  muscle  may  act  independently  of  the  rest.  In  the 
sheath  behind  the  muscle  the  epigastric  art.  ascends 
to  anastomose  with  the  int.  mammary. 

The  linese  semilunares  are  the  oblique  lines  on  the 
outer  edge  of  the  rectus,  formed  by  the  junction  of  the 
oblique  and  transversalis  tendons.  The  linea  alba  is 
the  tendinous  white  line  which  extends  from  the  xi- 
phoid cartilage  superiorly  to  the  pubes  inferiorly ;  it 
is  formed  by  the  intermingling  of  the  fibres  of  the  ob- 
lique and  transversalis  muscles,  is  thinner  and  wider 
above  than  below  the  umbilicus,  where  it  is  particu- 
larly dense. 

Post.  Abdominal  Muscle. 

Quadratus  Lumborum,  Or.  ileo  lumbar  lig.  and  two 
inches  of  the  crista  ilii;  Ins.  1,  lower  edge  of  the  in- 
ner half  of  the  last  rib ;  2,  by  four  processes  into  the 
four  upper  lumbar  transverse  processes  .  •.  enclosed  in 
a  sheath  like  the  rectus ;  vide,  Fascise.  Use,  to  draw 
down  the  ribs. 

Superior  Abdominal  Muscle. 

Diaphragm.     A  moveable  septum  between  the  tho- 
racic and  abdominal  cavities,  composed  of  a  central 
tendinous  portion,  surrounded  by  muscular  fibres. 
The  tendon  is  trilobate,  and  placed  nearly  in  the  cen- 
6* 


66  THE   DIAPHRAGM. 

tre  of  the  muscle;  above,  it  supports  the  heart  being 
in  the  adult  firmly  united  to  its  fibrous  pericardium : 
below,  it  covers  the  centre  of  the  liver.  The  middle 
and  largest  lobe  is  behind  the  xiphoid  cartilage;  the 
right,  the  next  in  size,  and  the  left,  the  smallest,  are 
directed  backwards  and  outwards  on  each  side.  The 
post,  margin  of  the  tendon  is  notched,  and  gives  at- 
tachment to  the  fixed  portion  of  the  muscle ;  the  ante- 
rior edge,  from  which  the  anterior  or  moving  portion, 
arises,  is  convex  and  concentric  with  the  infr.  margin 
of  the  thorax;  Or.  posterior  or  fixed  portion;  1,  the 
crura.  The  left  crus  arises  narrow  tendinous  from 
the  bodies  and  intervertebral  subs,  of  the  three  upper 
lumbar  vertebrae;  the  right,  which  is  more  in  front, 
arises  from  the  corresponding  vertebrae,  and  the  in- 
tervertebral substance  next  beyond.  Opposite  the 
first  lumbar  vert,  they  become  fleshy,  and  divide  into 
two  portions,  which  are  separated  by  the  splanchnic 
nerves;  the  outer  portions,  arems.  into  the  post  mar- 
gin of  the  tendon :  the  inner  decussate  in  front  of  the 
vert.  col.  to  form  the  aortic  opening,  diverge  to  form 
the  oesophageal  opening,  and  then  pass  on  to  the  cen- 
tral tendon.  2,  Another  portion  arises  from  the  false 
and  true  ligam.  arcuata  on  each  side  to  be  inserted 
into  the  remainder  of  the  notch.  The  ant.  portion, 
Or.  from  the  whole  of  the  convex  edge  of  the  tendon 
Ins.  base  of  the  xiphoid  cartilage,  and  by  six  or  seven 
digitations  into  the  inner  surfaces  and  upper  edges  of 
the  six  last  ribs,  where  it  intersects  with  the  m.  trans- 
versalis. 

The  edge  of  the  aortic  opening  is  tendinous;  it 
transmits  the  aorta,  vena  azygos,  and  thoracic  duct; 
the  cesophageal  opening  is  muscular;  it  transmits 
the  oesophagus  and  the  vagus  nerves.  The  opening  for 
the  vena  cava  is  tendinous  quadrangular,  and  tubu- 
lar, and  is  placed  at  the  junction  of  the  right  and 
middle  lobe  of  the  tendon .  •.  The  cellular  tissue  of  the 
mediastinum,  and  that  between  the  ant.  abdominal 


THE    PERITONEUM.  67 

muscles,  communicating  through  an  opening  on  each 
side  of  the  xiphoid  cart. 

SECTION  III. 
The  Abdominal  Viscera. 

The  abdomen  contains  the  organs  of  digestion  viz. : 
the  stomach  and  intestines,  the  liver,  pancreas,  and 
spleen,  and  in  addition,  the  kidneys,  supra-renal  cap- 
sules, and  ureters;  the  abdominal  aorta,  inf.  vena 
cava,  vena  porta,  thoracic  duct,  and  numerous  lym- 
phatic vessels  and  glands,  the  sympathetic  nerve,  and 
several  smaller  vessels  and  nerves. 

The  abdomen  is  lined  internally  by  the  Peritoneum ; 
this  is  the  largest  serous  membrane  in  the  body,  and 
lines  the  inner  surface  of  the  abdominal  parietes  as 
well  as  most  of  the  contained  organs. 

The  reflections  of  the  peritoneum  may  be  traced  as 
follows — from  the  umbilicus  it  passes  upwards,  lining 
the  inner  surface  of  the  tranversalis  and  recti  mus- 
cles, to  the  lower  margin  of  the  thorax ;  it  here  bends 
backwards,  lining  the  inf.  concave  surface  of  the  dia- 
phragm, sinking  deep  into  the  hypochondriac  region; 
on  the  left  it  is  reflected  on  the  back  part  of  the  sple- 
nic vessels,  to  the  post,  surface  spleen,  it  winds 
round  and  invests  this  organ,  then  passes  on  the  ant. 
surface  of  its  vessels  ;  in  the  centre  it  is  reflected  on 
the  stomach  so  as  to  enclose  this  organ,  and  pass  from 
its  margin  downwards  to  form  the  gastro  colic  omen- 
turn  ;  on  the  right  side  it  is  reflected  from  the  umbili- 
cus, enclosing  the  umbilical  vein,  and  forming  the 
suspensory  ligament  of  the  liver ;  it  invests  this  organ, 
and  passing  from  its  inferior  surface  encloses  the  he- 
patic vessels,  and  forms  the  gastro-hepatic  fold  or 
omentum;  from  the  diaphragm  the  peritoneum  de- 
scends on  the  liver,  and  forms  the  lateral  ligaments  of 
this  organ ;  from  the  convex  or  inferior  border  of  the 
•  stomach  the  two  layers  of  peritoneum  unite  to  form 
the  gastro-colic  ornentum,  which  passes  downwards  in 


68  THE    PERITONEUM. 

front  of  the  transverse  arch  of  the  colon,  descends 
lower  on  the  left  than  on  the  right  side,  becomes  re- 
flected on  itself,  so  as  to  consist  of  four  layers ;  the 
two  posterior  layers  ascend  until  they  reach  the  trans- 
verse colon;  they  here  separate  so  as  to  enclose  this 
intestine,  and  from  its  concave  margin  unite  and  de- 
scend to  form  the  transverse  meso  colon ;  opposite  the 
duodenum  this  fold  separates  into  an  ascending  and 
descending  layer,  enclosing  the  inferior  portion  of  this 
intestine ;  the  ascending  layer  passes  in  front  of  the 
lower  and  middle  portions  of  the  duodenum  and  of  the 
pancreas  to  the  posterior  surface  of  the  right  lobe  of 
the  liver,  where  it  is  continuous  with  the  peritoneum 
lining  this  organ  and  the  posterior  layer  of  the  lower 
or  gastro-hepatic  omentum;  the  descending  layer 
passes  downwards  into  the  lumbar  region,  where  it 
becomes  continuous  with  the  right  and  left  meso  co- 
lon ;  in  the  centre  the  inferior  layer  of  the  transverse 
meso  colon  passes  in  front  of  the  spinal  column  and 
the  large  blood-vessels  resting  upon  it,  and  is  thence 
reflected  downwards  and  forwards  so  as  to  enclose  the 
small  intestines  and  the  mesenteric  vessels  and  form 
the  mesentery. 

Inferiorly  the  peritoneum  descends  from  the  umbi- 
licus in  the  centre,  enclosing  the  urachus,  and  form- 
ing a  slight  projection,  it  then  descends,  lining  the 
posterior  surface  of  the  rectus  muscle  to  near  the 
pubes;  it  than  passes  backwards,  sinks  into  the  pel- 
vis, lines  the  upper  posterior  and  part  of  the  lateral 
surface  of  the  bladder  as  low  down  as  near  to  the  pos- 
terior extremity  of  the  vesiculse  seminales  and  pros- 
tate gland,  whence  it  is  reflected  on  to  the  anterior 
surface  of  the  rectum  and  the  sides  of  the  pelvis  form- 
ing the  posterior  and  lateral  false  ligaments  of  the 
bladder;  the  peritoneum  now  ascends,  investing  the 
middle  and  upper  thirds  of  the  rectum,  forming  the 
meso  rectum,  whence  it  passes  on  each  side  to  line  the 
jliac  fossae,  and  becomes  continuous  with  that  lining 
he  abdominal  parietes.  In  the  female  the  peritoneum 


THE    STOMACH.  69 

is  reflected  from  the  posterior  surface  of  the  bladder 
on  the  upper  and  back  part  of  the  vagina,  whence  it 
passes  upwards  on  the  uterus  so  as  to  invest  this,  and 
form  on  each  side  the  broad  ligaments  of  this  organ, 
and  from  it  passes  upon  the  rectum  as  in  the  male 
subject.  On  either  side  the  peritoneum  covers  par- 
tially the  caecum  and  signoid  flexure  of  the  colon,  and 
binds  them  down  in  the  iliac  fossa. 

On  each  side  of  the  mesial  line  inferiorly,  the  peri- 
toneum is  thrown  into  an  oblique  fold  by  the  degene- 
rated umbilical  artery,  and  thus  are  formed  the  ingui- 
nal pouches  one  on  each  side  of  the  umb.  art. 

The  peritoneum  in  the  female  does  not  form  a  shut 
sac,  as  an  opening  exists  in  it,  where  it  covers  the 
fimbriated  extremities  of  the  Fallopian  tubes;  here 
the  serous  and  mucous  membranes  are  continuous. 

The  principal  folds  formed  by  the  peritoneum  are: 
The  gastro  hepatic,  or  lower  omentum,  consists  of  two 
layers,  and  extends  from  the  transverse  fissure  of  the 
liver  to  the  concave  margin  of  the  stomach ;  it  contains 
between  its  layers  the  hepatic  art.  to  the  left  side ; 
the  ductuscholedochus to  the  right,  and  the  venaporta 
behind  and  between  both ;  these  are  surrounded  by 
cellular  tissue,  and  form  the  capsule  of  Glisson,  behind 
which  is  the  foramen  of  Winslow  leading  into  the  great 
bag  of  the  omentum. 

The  gastro  colic,  or  great  omentum,  the  meso  cx»lon, 
meso  rectum,  and  mesentery  have  been  already  suffi- 
ciently described.  The  great  bag  of  the  omenturn  ex- 
tends from  the  foramen  of  Winslow  to  the  bottom  of 
the  great  omentum;  it  is  bounded  in  front  b}r  the 
lesser  omentum,  the  stomach,  and  the  descending 
layer  of  the  great  omentum;  and  posteriorly  by  its 
ascending  layer. 

The  hollow  viscera  of  the  abdomen  consists  of  the 
stomach,  the  small  and  large  intestines. 

The  STOMACH,  the  principal  organ  of  digestion,  is 
situated  in  the  left  hypochondriac  and  epigastric  re- 
gions ;  it  extends  from  its  cardiac  or  oesophageal  ex,- 


70  ARTERIES    OF    STOMACH. 

tremity  downwards  and  forwards,  and  near  its  pyloric 
extremity  turns  a  little  upwards  and  backwards;  it  is 
curved  and  irregular  in  shape,  and  has  two  orifices, 
two  curves,  and  two  extremities. 

The  cardiac  orifice  communicates  with  the  oesopha- 
gus, and  is  nearly  circular;  itspyloric  orifice  is  situ- 
ated towards  the  right  side,  anterior  to  the  cardiac; 
it  is  also  circular,  and  communicates  with  the  duode- 
num; the  left,  or  great  bulging  extremity  of  the  sto- 
mach, lies  in  front  of  the  spleen;  the  right,  much 
smaller,  terminates  in  the  pylorus;  the  concave,  or 
lesser  edge  of  the  stomach  is  turned  upwards  and 
backwards,  and  has  attached  to  it  the  lesser  omentum, 
the  coronary  vessels  and  nerves  run  along  it.  The 
great,  or  convex  edge,  is  directed  downwards  and  for- 
wards, and  has  attached  to  it  the  great  omentum,  the 
epiploic  vessels  and  nerves  run  along  this  border ;  the 
anterior  surface  of  the  stomach  is  convex,  the  poste- 
rior nearly  flat. 

The  stomach  is  composed  of  four  coats,  the  serous, 
muscular,  nervous  or  fibrous,  and  the  mucous;  the  se- 
rous coat  is  derived  from  the  peritoneum,  and  has  been 
already  described.  The  muscular  layer  consists  of 
three  sets  of  fibres ;  the  longitudinal  are  derived  from 
the  fibres  of  the  oesophagus,  and  are  best  marked  along 
the  lesser  and  greater  curves;  the  circular  fibres  sur- 
round this  organ  at  the  junction  of  its  right  third  with 
its  left  extremity ;  th.ey  sometimes  contract  so  as  to 
give  to  the  stomach  an  hour-glass  shape ;  the  irregular 
or  oblique  fibres  are  situated  chiefly  around  the  great 
bulging  extremity. 

The  nervous  or  fibrous  coat  of  the  stomach  lies  be- 
neath the  preceding ;  it  is  composed  of  condensed  cel- 
lular tissue,  and  strengthens  the  stomach  considerably ; 
the  mucous  coat  lines  the  interior  of  the  stomach;  it 
is  of  a  rose  pink  colour,  and  is  thrown  into  irregular 
folds,  the  rugae  of  this  organ;  at  the  pylorus  this  forms 
a  distinct  valve,  having  beneath  it  well-marked  circu- 
lar muscular  fibres. 


THE   SMALL   INTESTINES.  71 

The  stomach  is  supplied  with  blood  from  the  coro- 
nary arteries,  a  branch  of  the  coeliac  axis,  which  runs 
along  its  lesser  curve,  the  right  gastro-epiploic,  a 
branch  from  the  hepatic,  and  the  left  gastro-epiploic, 
a  branch  of  the  splenic.  Its  nerves  proceed  from  the 
pneumogastric  or  par  vagum  and  the  solar  plexus. 

The  SMALL  INTESTINES  consist  of  the  duodenum  je- 
junum, and  ileum.  The  duodenum  is  about  twelve 
inches  in  length,  and  extends  from  the  pylorus  to  the 
root  of  the  mesentry;  it  lies  chiefly  in  the  right  hy- 
pochondrium,  and  reaches  into  the  umbilical  and  left 
lumbar  regions,  it  forms  an  irregular  horse-shoe 
curve,  in  the  concavity  of  which  lies  the  head  of  the 
pancreas,  and  consists  of  three  portions — the  superior 
transverse,  the  vertical  and  the  inferior  transverse — 
the  first  passes  upwards  and  to  the  right  side  as  far 
as  the  neck  of  the  gall-bladder;  the  second  descends 
along  the  right  side  of  the  spinal  column  in  front  of 
the  right  kidney;  the  third  portion  passes  transversely 
across  the  spine,  in  front  of  the  second  lumbar  verte- 
bra, and  behind  the  sup.  mesenteric  art.  terminates 
in  the  jejunum. 

The  duodenum  has  four  coats,  the  external  or  se- 
rous is  only  partial,  the  superior  portion  is  entirely 
covered  by  peritoneum,  the  middle  wants  this  mem- 
brane posteriorly,  and  the  inferior  portion  is  unco- 
vered, lying  between  the  folds  oT  the  meso  colon;  its 
muscular  fibres  are  chiefly  circular,  its  fibrous  coat 
resembles  that  of  the  stomach,  its  mucous  coat  is 
thrown  into  numerous  folds  at  its  lower  third,  form- 
ing the  valvulse  connivcntes.  The  ductus  communis 
choledochus  and  the  pancreatic  duct  open  into  the 
concave  margin  of  the  duodenum,  near  to  and  a  little 
above  the  angle  of  junction  between  its  descending 
and  inferior  transverse  portions,  generally  on  one  of 
the  valvulse  conniventes ;  its  orifice  is  marked  by  a 
slight  thickening  of  the  membrane, 

The  jejunum  forms  two-fifth  of  the  small  intestines, 


72  THE  LARGE  INTESTINES. 

the  ileum  the  remaining  three-fifths ;  their  structure 
is  nearly  similar,  consisting  of  an  external  serous  coat 
a  muscular  coat,  composed  chiefly  of  circul.  fibres,  a 
fibrous  coat,  and  a  mucous  lining  membrane,  thrown 
into  numerous  folds,  the  valvulae  conniventes.  These 
are  most  numerous  in  the  jejunum,  least  so  in  the 
lower  part  of  the  ileum. 

The  small  intestines  are  supplied  with  blood,  the 
duodenum  chiefly  from  the  gastro  duodenalis  art., 
the  jejunum  and  ileum  from  the  superior  mesenteric 
art.  Their  nerves  are  derived  from  the  solar  plexus. 

In  the  interior  of  the  small  intestines  are  numerous 
glands.  They  are  isolated  in  the»upper  part,  forming 
the  glandulae  solitarae,  or  the  glands  of  Brunner,  but 
in  the  lower  part  are  collected  in  oval  groups  form- 
ing the  glandulse  agminatae,  or  the  glands  of  Peyer. 

At  its  lower  extremity  the  ileum  ascends  from  the 
pelvic  cavity,  and  terminates  opposite  the  right 
sacroiliac  symphysis  in  the  caecum  or  caput  coli. 

The  LARGE  INTESTINES  consist  of  the  caecum, 
colon,  and  rectum. 

The  c&ciim,  or  caput  coli,  is  lodged  in  the  right  iliac 
fossa,  is  irregular  in  shape,  and  larger  than  any  other 
part  of  the  large  intestines ;  it  receives  the  end  of  the 
ileum  at  its  internal  and  posterior  side,  some  distance 
above  its  lower  extremity,  and  is  continuous  with  the 
colon;  its  coats  consist  of  a  partial  serous  covering, 
deficient  posteriorly,  longitudinal,  and  a  few  circular 
muscular  fibres,  a  fibrous  coat,  and  a  lining  mucous 
membrane;  its  interior  is  irregular,  and  presents  at 
its  junction  with  the  ileum  a  double  valve,  the  ileo 
csecal  valve;  the  inferior  portion  of  this  valve  is  the 
larger,  and  somewhat  vertical,  the  superior  is  more 
horizontal;  the  structure  of  these  valves  is  a  fold  of 
mucous  membrane  enclosing  some  muscular  fibres. 
The  appendix  vermiformis,  a  small  worm-like  intes- 
tine, proceeds  from  the  left  and  posterior  surface  of 
the  caecum;  its  cavity  is  small,  and  communicates 
with  the  end  of  the  caecum. 


THE   RECTUM.  73 

The  colon  extends  from  the  caecum  to  the  rectum, 
and  is  divided  into  the  right  ascending,  the  transverse, 
left  descending,  and  the  sigmoid flexure.  The  ascend- 
ing colon  is  situated  in  the  right  lumbar  region,  in 
front  of  the  right  kidney  and  renal  vessels,  the  trans- 
verse colon  passes  across  the  spine  to  the  left  side, 
forming  an  arch,  the  convexity  forwards,  and  joins 
the  descending  colon ;  this  is  situated  in  the  left  lum- 
bar region  in  front  of  the  left  kidney  and  renal  ves- 
sels, and  joins  inferiorly  the  sigmoid  flexure;  this  is 
lodged  in  the  left  iliac  fossa  resting  on  the  psoas,  quad- 
ratus  lumborum,  and  iliacus  internus  muscles.  The 
structure  of  the  colon  is  similar  to  that  of  the  caecum, 
in  all,  the  longitudinal  muscular  fibres  are  collected 
into  three  longitudinal  bands ;  these  proceed  from  the 
appendix  vermiformis,  and  are  lost  in  the  rectum ; 
one  of  these  is  anterior,  the  other  two  are  on  the  pos- 
terior surface ;  on  their  outer  surface  are  the  appen- 
dices epiploicse,  folds  of  peritoneum  enclosing  some  adi- 
pose tissue.  The  large  intestines  are  supplied  with 
blood  from  the  inf.  mesenteric  art.;  their  nerves  are 
derived  from  the  sympathetic. 

The  rectum  descends  into  the  pelvis  from  the  sig- 
moid flexure  of  the  colon;  it  proceeds  from  the  left 
sacro  iliac  symphy  sis,  at  first  downwards  and  inwards 
towards  the  mesial  line  of  the  sacrum,  it  then  bends 
downwards  and  forwards  towards  the  perineum  and 
beneath  the  bladder,  and  finally  turning  a  little  back- 
wards, it  terminates  in  the  anus ;  concave  in  front,  it 
receives  the  posterior  surface  of  the  bladder,  and  rests 
in  the  hollow  of  the  sacrum ;  on  each  side  of  it  are  the 
internal  iliac  vessels  and  sacral  plexus.  The  structure 
of  the  rectum  consists  of  a  serous  coat;  this  is  only 
partial,  the  upper  third  is  entirely  covered,  the  middle 
third  wants  this  covering  on  its  posterior  surface,  and 
the  lower  third  is  wholly  uncovered  by  it;  a  muscular 
coat  composed  of  reddish  longitudinal  fibres,  which 
above  the  anus  assume  a  circular  shape,  forming  the 
7 


74  THE    LIVER. 

deep  sphincter  ani  muse.,  a  fibrous  coat,  well  marked, 
and  lastly  a  lining  mucous  membrane;  this  is  thrown  in- 
to longitudinal  folds  in  the  undisturbed  state.  Some 
have  described  also  transverse  folds,  but  they  do  not 
exist. 

The  arteries  of  the  rectum  are  derived  from  three 
sources,  the  superior  hemorrhoidal  from  the  inf.  me- 
senteric,  the  middle  from  the  internal  iliac,  and  the 
inferior  from  the  internal  pudic;  its  nerves  are  derived 
from  the  sacral  and  sympathetic.  The  absorbents  of 
the  intestines  are  extremely  numerous,  those  of  the 
small  intestines  absorb  the  chyle,  and  are  hence  called 
lacteals;  they  pass  through  the  mesenteric  glands  con- 
tained in  the  folds  of  the  mesentery,  and  terminate  in 
the  receptaculum  chyli,  the  commencement  of  the  tho- 
racic duct;  the  absorbents  from  the  large  intestines 
pass  through  the  lumbar  glands,  and  terminate  also 
in  the  thoracic  duct. 

The  glandular  viscera  of  the  abdomen  subservient 
to  the  function  of  digestion  are  the  liver,  pancreas, 
and  spleen. 

The  LIVER  is  situated  in  the  right  hypochondriac 
and  epigastric  regions,  of  greater  extent  transversely 
than  vertically;  its  anterior  surface,  concave,  is  .di- 
vided into  two  by  the  falsiform  ligament,  and  is  in 
contact  with  the  diaphragm;  its  posterior  surface,  ir- 
regularly concave,  rests  on  the  pyloric  end  of  the  sto- 
mach, the  duodenum,  and  upper  extremity  of  the 
right  kidney;  its  upper  margin  is  obtuse  and  con- 
nected to  the  diaphragm  by  folds  of  the  perito- 
neum, and  the  inf.  vena  cava;  its  lower  margin  is  thin, 
and  notched  near  its  centre  by  the  umbilical  vein ; 
its  lateral  margins  are  rounded. 

The  liver  is  divided  into  two  lobes,  the  right  and 
left,  by  the  attachment  of  the  falsiform  lig.  on  its  con- 
vex surface,  and  by  the  longitudinal  fissure  lodging 
the  umbilical  vein,  and  ductus  venosus,  on  its  concave 
surface;  the  left  lobe  is  the  smaller,  and  is  not  sub- 


STRUCTURE   OF   LIVER.  75 

divided.  From  the  junction  of  the  superior  and  mid- 
dle thirds  of  the  longitudinal  fissure,  the  transverse  fis- 
sure proceeds  to  the  right  side  through  the  middle 
third  of  the  liver;  it  lodges  the  two  branches  of  the  ve- 
na porta,  the  hepatic  art.,  and  hepatic  duct;  the  hori- 
zontal fissure  runs  from  the  anterior  to  the  posterior 
margin  of  the  liver,  and  lodges  the  umbilical  vein,  and 
its  continuation,  the  ductus  venosus. 

Besides  these  fissures  there  are  two  depressions  on 
the  concave  surface  of  the  liver,  one  for  the  vena  cava, 
sometimes  a  canal,  between  the  lobulus  Spigelii  and 
right  lobe;  another  for  the  gall  bladder  to  the  right 
of  the  horizontal  and  in  front  of  the  transverse  fissure. 
The  right  kidney  and  colon  sometimes  mark  this 
surface. 

On  this  surface  are  the  three  lobules  of  the  liver — 
viz.,  lobulus  Spigelii,  pyramidal  in  shape,  its  apex  free, 
having  the  longitudinal  fissure  to  its  left,  the  vena  ca- 
va to  its  right,  and  the  transverse  fissure  in  front;  a 
tail-like  process,  lobulus  caudatus,  connects  it  with  the 
rest  of  the  right  lobe;  lobulus  quadratus  is  bounded  to 
the  left  by  the  horizontal  fissure,  to  the  right  by  the 
gall  bladder,  superiorly  by  the  transverse  fissure,  in 
front  by  the  thin  margin. 

The  liver  has  two  coats,  a  serous  and  a  fibrous ;  the 
serous  or peritonealis partial,  as  it  does  not  cover  the 
organ  at  the  fissures,  behind  the  gall  bladder  and  vena 
cava,  and  within  the  coronary  ligament;  it  forms  the 
right  and  left  lateral,  coronary,  and  falsiform  liga- 
ments; the  first  two  connects  the  respective  lobes  to 
the  diaphragm,  the  second  surround  the  orifices  of  the 
vena  cava  hepat.,  the  last  has  been  already  described. 
Ike  fibrous  coat  is  tolerably  well  marked,  and  passes 
into  the  interior  of  theliver  with  its  vessels.  The  struc- 
ture of  the  liver  consists  of  a  number  of  granules,  of 
a  brownish  yellow  colour,  united  by  cellular  tissue. 

Mr.  Kiernan  has  described  the  structure  of  the  liver 
as  composed  of  lobular  bodies,  which  are  found  in  all 
parts  of  the  organ,  but  in  the  centre  are  of  an  angu- 


76  THE    GALL   BLADDER. 

lar  shape,  while  towards  the  circumference  they  ac- 
quire a  more  rounded  form;  running  down  their  mid- 
dle is  the  intralobular  vein,  into  which  still  more  mi- 
nute branches  pour  their  blood;  at  the  base  of  the  lo- 
bules these  veins  open  into  a  larger  one,  called  sublo- 
bular;  several  of  these  join  together,  and  by  their 
union  form  the  hepatic  vein,  which  terminates  in  the 
vena  cava;  around  the  intralobular  vein  ramify  the 
vena  porta,  ductus  hepaticus,  and  hepatic  art.,  exter- 
nal to  which  is  the  capsular  covering;  in  passing  to 
and  from  these  lobules  the  vessels  ramify  between 
them,  and  form  interlobular  vessels ;  the  portal  vein  in 
the  vaginal  sheath  gives  off  numerous  branches, 
which,  previous  to  entering  between  the  lobules, 
form  the  vaginal  plexus. 

The  liver  is  supplied  with  blood  by  the  hepatic  art. 
and  vena  porta,  which  pass  transversely  across  the 
organ,  each  of  them  having  a  coating  of  cellular  tis- 
sue derived  from  the  capsule  of  Glisson,  and  hence 
collapse  when  cut  across;  the  blood  is  returned  by 
the  venae  cavae  hepaticae,  which  unite  into  three  or 
four  large  trunks,  and  terminate  in  the  vena  cava 
where  it  passes  through  the  diaphragm ;  these  ves- 
sels have  no  cellular  covering,  remain  open  when 
cut  across,  and  take  a  longitudinal  course. 

The  bile  is  conducted  from  the  liver  by  the  biliary 
ducts;  these  arise  from  the  granules,  and  finally  unite 
so  as  to  form  two  ducts,  one  for  each  lobe,  which  again 
unite -and  form  the  hepatic  duct;  this  escapes  from 
the  transverse  fissure  and  unites  with  the  cystic  duct 
to  form  the  ductus  communis  choledochus,  about  three 
inches  in  length ;  it  conveys  the  bile  into  the  duo- 
denum. 

The  gall  bladder  is  lodged  in  a  sulcus  on  the  under 
surface  of  the  liver,  to  the  right  of  the  lobulus  caudatus; 
pyriform  in  shape,  its  larger  ext.  is  free,  and  projects 
beyond  the  thin  margin  of  the  liver,  its  smaller  ext. 
terminates  in  the  cystic  duct;  this,  about  an  inch  and  a 


PANCREAS.  77 

half  in  length,  unites  with  the  hepatic  duct  to  form 
the  ductus  communis  choledochus.  The  structure  of 
the  gall  bladder  is  composed  of  three  coats;  the  ext. 
serous  is  a  partial  coat  and  binds  it  down  in  situ;  the 
second  is  fibrous,  and  the  third  is  mucous;  this  is 
honeycomb  in  appearance,  and  is  tinged  with  the  bile. 
The  structure  of  all  these  ducts  is  the  same,  namely 
fibro-mucous,  as  are  all  the  excretory  ducts  of  the 
body  except  the  thoracic  duct. 

The  PANCREAS  lies  across  the  spine  behind  the 
stomach  and  between  the  two  layers  of  the  transverse 
meso-colon;  it  is  composed  of  a  larger  extremity  or 
head,  which  lies  in  the  concavity  of  the  duodenum ;  a 
lesser  ext.  or  tail,  reaching  to  the  spleen,  and  a  cen- 
tral portion,  or  body ;  its  structure  resembles  that 
of  the  salivary  glands. 

The  Pancreatic  duct  is  seen  on  its  posterior  sur- 
face ;  it  arises  by  numerous  radicles,  which  unite  and 
form  the  trunk;  this  conveys  the  pancreatic  fluid 
into  the  duodenum.  Its  structure  is  fibro-mucous. 
The  pancreas  is  supplied  with  blood  from  the  splenic 
and  the  pancreatico  duodenalis  art. 

The  SPLEEN  is  situated  in  the  left  hypochondrium, 
behind  the  great  bulging  ext.  of  the  stomach,  and 
above  the  left  kidney.  It  is  a  soft  spongy  mass,  of  a 
crescentic  shape  ;  the  concavity,  turned  inwards,  re- 
ceives the  vessels  and  nerves.  The  convexity  is  in 
contact  with  the  abdominal  parietes  beneath,  and  the 
diaphragm  above.  The  coats  of  the  spleen  are  a  se- 
rous and  fibrous,  the  former  nearly  perfect,  the  latter 
weak  and  thin;  its  internal  structure  is  composed  of 
shreds  of  cellular  tissue  filled  with  blood.  The  spleen 
is  supplied  with  blood  from  the  splenic  art.;  its  nerves 
are  derived  from  the  sympathetic. 

The  principal  vessels  of  the  abdomen  are  the  aorta 
and  its  branches,  the  vena  cava  inferior,  and  the  vena 
porta.  (See  Vascular  System.)  The  principal  nerves 
are  the  symphathetic  and  the  lumbar  plexus,  lying 


78  HERNIA. 

imbeded   in  the  psoas   mag.  muse.     (See  Nervous 
System.) 

SECTION  IV. 

HERNIA. 

The  anatomy  of  hernia  is  intimately  connected 
with  that  of  the  abdominal  parietes,  and  may  well 
be  considered  here. 

Inguinal  hernia^  so  called  from  its  appearance  in 
the  inguinal  region  or  groin;  of  it  we  have  two  varie- 
ties, one  named  oblique  inguinal  hernia,  from  the  ob- 
lique direction  which  the  tumour  takes  between  the 
abdominal  muscles,  following  the  course  of  the  sper- 
matic cord,  whence  it  is  also  occasionally  called  sper- 
matocele — the  other  is  called  direct  inguinal  hernia, 
from  its  protruding  directly  forwards  through  the 
external  abdominal  ring. 

Femoral  hernia  appears  in  the  upper  inner  and  an- 
terior part  of  the  thigh,  where  it  descends  beneath 
Poupart's  ligament  on  the  inner  side  of  the  femoral 
vessels. 

Umbilical  hernia  protrudes  through  the  umbilicus, 
taking  the  course  of  the  umbilical  cord. 

The  term  Ventral  hernia  indicates  the  protrusion  of 
one  or  more  of  the  viscera  through  some  other  re- 
gion of  the  abdomen  than  those  specifically  mention- 
ed; the  situations  where  this  species  of  hernia  most 
frequently  occurs,  are  at  the  linea  alba,  the  linese 
semilunares  and  transversse.  The  other  forms  of  th  e 
disease  are  of  minor  importance. 

Oblique  Inguinal  Hernia. 

In  this  form  of  the  disease,  the  hernia  takes  the 
course  of  the  spermatic  canal  with  the  spermatic 
cord ;  that  is,  it  escapes  from  the  abdomen  at  the  in- 
ternal abdominal  ring,  about  midway  between  the 
spine  of  the  ilium  and  the  symphysis  pubis,  descends 
obliquely  forwards  and  inwards,  escapes  throughout 


SUPERFICIAL  FASCIA.  79 

the  external  abdominal  ring,  and  finally  descends 
into  the  scrotum. 

On  raising  the  skin  a  dense  layer  of  cellular  sub- 
stance is  brought  into  view — this  is  the  superficial 
fascia  of  inguinal  hernia.  This  is  perfectly  continuous 
with  the  common  subcutaneous  cellular  tissue  beneath 
the  integuments  in  other  regions  of  the  body,  and  dif- 
fers but  little  from  it,  except  in  being  a  little  denser 
in  structure,  and  of  more  importance  from  its  con- 
nexion with  hernia.  Above,  the  superficial  fascia  is 
continuous  with  the  cellular  tissue  covering  the  lower 
surface  of  the  thorax,  and  upper  part  of  the  abdomi- 
nal muscles;  inferiorly  it  descends  over  Poupart's 
ligament  into  the  thigh,  and  there  becomes  continu- 
ous with  the  superficial  fascia  of  the  femoral  region ; 
nearer  the  pubes  it  passes  over  the  spermatic  cord  in 
the  male,  and  descends  into  the  scrotum  and  perineum, 
where  it  identifies  itself  with  the  loose  cellular  tissue 
of  these  regions.  On  the  mesial  line,  the  superficial 
fascia  descends  from  the  linea  alba,  on  the  dorsum  of 
the  penis,  and  here  forms  a  tolerably  dense  structure, 
the  false  suspensory  ligament  of  the  penis,  which 
connects  this  organ  to  the  abdominal  parietes.  In 
the  female  it  is  loaded  with  a  quantity  of  adipose 
tissue  and  descends  into  thelabium.  The  cutaneous 
surface  of  the  superficial  fascia  is  rough  and  cellular, 
and  is  intimately  connected  to  the  integuments;  its 
deep  surface  is  more  compact  and  smooth,  and  is  ap- 
plied against  Scarpa's  fascia,  which  thus  separates 
it  from  the  abdominal  muscles.  The  use  of  this  fascia 
is  to  allow  of  the  free  motions  of  the  integuments  on 
the  abdominal  muscles,  and  to  assist  these  in  the 
support  of  the  abdominal  viscera. 

Some  anatomists  have  divided  the  superficial  fascia 
into  several  layers;  this  is  quite  an  arbitary  division, 
and  without  any  practical  advantage,  as  the  number 
of  layers  varies  in  almost  every  subject,  and  depends 
much  on  the  dexterity  of  the  operator;  its  thickness 
also  varies  much  in  different  individuals,in  some  being 


80  SCARPA'S  FASCIA. 

but  a  few  in  others  many  lines  in  depth.  In  it  we  meet 
with  several  superficial  arteries,  veins,  nerves,  and 
lymphatic  glands.  The  arteries  are  the  external  epi- 
gastric, and  branches  from  the  external  circumflexa 
ilii,  and  pubic  arteries.  They  arise  from  the  femoral 
artery  a  little  below  Poupart's  ligament,  ascend  in 
front  of  the  ligament,  and  are  lost  in  the  superficial 
fascia  and  integuments.  The  external  epigastric  is 
the  largest,  it  ascends  obliquely  inwards,  towards  the 
umbilicus,  where  it  terminates.  The  nerves  are  small, 
and  are  derived  from  branches  of  the  lumbar  plexus. 
The  lymphatic  glands  are  four  or  five  in  number ;  they 
take  a  nearly  transverse  course,  parallel  to  Poupart's 
ligament,  some  lying  a  little  above,  others  somewhat 
beneath  the  ligament.  They  are  named  the  superior 
inguinal  glands,  to  distinguish  them  from  another  set 
of  inguinal  glands,  met  with  below  Poupart's  liga- 
ment more  numerous,  and  arranged  in  the  vertical 
direction;  they  are  contained  in  a  sheath  or  capsule 
formed  in  the  superficial  fascia.  The  superior  set 
communicates  with  the  absorbents  of  the  genital  or- 
gans. The  inferior  inguinal  glands,  on  the  contrary, 
communicate  with  the  absorbents  of  the  lower  extre- 
mity. 

On  raising  superficial  fascia  a  distinct  layer  of  cel- 
lular tissue  "Scarpa's  fascia,"  is  exposed.  This  is 
firmly  attached  to,  and  appears  to  arise  from  the  fas- 
cia lata,  abouthalf  an  inchbelowPoupart'sligament, 
whence  it  ascends  over  the  ligament,  to  be  gradually 
lost  on  the  outer  surface  of  the  external  oblique  mus- 
cle :  it  is  sometimes  described  as  the  deep  layer  of 
the  superficial  fascia,  with  which  it  is  so  intimately 
connected,  as  to  give  to  this  the  appearance  of  being 
firmly  attached  to  Poupart's  ligament;  they  are,  in- 
deed, with  difficulty  separated. 

On  Scarpa's  fascia  femoral  hernia  rests  when  it 
turns  up  over  Poupart's  ligament.  These  fasciae, 
excepting  the  skin,  form  the  most  superficial  co- 
verings of  an  inguinal  hernia. 


PILLARS  OF  RING.  81 

On  raising  Scarpa's  fascia  the  outer  surface  of  the 
external  oblique  muscle  is  brought  into  view:  this  is 
here  perfectly  tendinous,  in  order  that  itmay  the  more 
effectually  support  the  abdominal  viscera ;  it  forms, 
with  the  fellow  of  the  opposite  side,  a  broad  sheet  of 
tendon,  extending  directly  across  the  lower  part  of  the 
abdomen.  Each  tendon  is  somewhat  triangular  in 
shape:  one  margin  is  turned  inwards,  and  unites  with 
its  fellow  on  the  mesial  line,  to  form  the  linea  alba ;  a 
second  is  directed  upwards  and  outwards,  slightly 
concave,  and  gives  attachment  to  the  fleshy  fibres  of 
the  muscle ;  the  third  margin  is  turned  downwards 
and  outwards  and  here  presents  a  thickened  con- 
densed cord,  named  Poupart's  ligament. 

The  tendinous  fibres  of  the  external  oblique  muscle 
are  distinct  and  well  marked :  by  far  the  greater  num- 
ber take  a  direction  downwards  and  inwards ;  a  few 
may  be  observed  to  decussate  with  these  taking  an 
oblique  course  upwards  and  inwards.  As  we  trace 
them  towards  the  pubes,  they  increase  in  strength  and 
density,  and  having  arrived  within  about  an  inch  and 
a  half  of  this  bone,  they  separate  into  two  bands,  and 
thus  leave  an  interval  between  them,  named  the  ex- 
ternal abdominal  ring.  The  bands  are  named  the 
pillars  of  the  ring.  One  of  them,  the  internal,  lies 
anterior  and  superior  to  the  other;  it  is  a  broad  flat 
sheet  of  tendon,  which,  passing  inwards,  descends  in 
front  of  the  symphysis  pubis,  into  which  it  is  implan- 
ted, decussating  with  its  fellow  of  the  opposite  side. 
A  few  fibres  pass  from  it  to  be  continuous  with  the 
fascia  lata  of  the  opposite  side ;  others  may  be  traced 
descending  on  the  dorsum  of  the  penis,  contributing 
to  form  the  true  suspensory  ligament  of  this  organ. 
The  external  pillar  of  the  ring,  is  stronger  and  shorter 
than  the  other,  is  a  continuation  of  Poupart's  liga- 
ment :  it  is  a  round  fibrous  cord ;  it  descends  inwards, 
and  is  inserted  into  the  spine  or  tubercle  of  the  pubes ; 
on  it  the  spermatic  cord  rests  as  it  escapes  through 
the  ring.  Here  the  external  pillar  is  excavated  on 


82  PILLARS  OF  RING. 

its  superior  surface  (as  will  be  seen  in  a  future 
stage  of  the  dissection)  to  accommodate  the  cord, 
and  thus  preserve  it  from  injury. 

Inferiorly,  or  towards  the  thigh,  the  descending  fibres 
of  the  external  oblique  muscle  become  condensed 
and  form  Poupart's  ligament,  a  dense  fibrous  cord, 
which  descends  inwards  from  the  anterior  superior 
spinous  process  of  the  ilium  to  the  pubes,  into  which 
itis  implanted  by  two  attachments  ;  one,  already  de- 
scribed as  the  external  pillar  of  the  ring,  is  inserted 
into  the  spine  or  tubercle  of  the  pubes;  the  other  is 
an  expansion  from  this,  and  forms  a  broad  thin  liga- 
ment, which  ascends  obliquely  inwards,  to  be  inserted 
into  the  internal  extremity  ofthelineainnominata;  it 
is  named  Gimbernaut 's  ligament,  or  third  insertion  of 
the  crural  arch.  It  lies  superior  and  posterior  to  the 
external  pillar  of  the  ring,  or  second  insertion  of 
Poupart's  ligament.  Itis  more  immediately  connect- 
ed with  femoral  hernia,  with  which  we  shall  here- 
after describe  it  more  minutely. 

Near  the  ilium  Poupart's  ligament  is  thin  and 
weak,  but  it  increases  much  in  density  as  it  aproaches 
the  pubes.  Its  inferior  margin  slightly  concave, 
and  directed  somewhat  forwards,  gives  attachment 
to  the  iliac  portion  of  the  fascia  lata.  To  its  superior 
edge  are  connected  the  external  and  internal  oblique, 
and  transversalis  muscles,  and  the  transversalis  and 
iliac  fasciae. 

A  few  tendinous  fibres  of  the  external  oblique 
muscle  decussate  with  those  just  described;  they  are 
the  inter  columnal  bands.  They  arise  from  near  Pou- 
part's ligaments, ascend  inwards,  forming  curves  con- 
vex towards  the  pubes,.  and  are  gradually  lost  in  the 
tendon  as  they  approach  the  linea  alba;  towards  the 
ilium  they  are  indistinct,  but  near  the  pubes  they  be- 
come strong  and  well  marked ;  in  general  one  strong- 
er than  the  rest  rounds  off  the  apex  of  the  external 
abdominal  ring,  and  thus  assists  in  restraining  the 
increase  of  this  opening.  The  use  of  the  intercolumnal 


EXTERNAL  ABDOMINAL  RING.  83 

bands  is  to  prevent  the  separation  of  the  descending 
fibres  of  the  external  oblique,  between  which,  inter- 
vals occasionally  exist,  exposing  the  fibres  of  the 
internal  oblique  muscle. 

Hitherto  the  external  abdominal  ring  has  not  been 
sufficiently  apparent ;  it  is  concealed  from  view  by  a 
layer  of  cellular  tissue,  the  external  spout-like  or  Cam- 
per's fascia,  or  intercolumnal  fascia,  which  descends 
from  the  edges  or  margins  of  the  ring,  on  the  spermatic 
cord,  upon  which  it  is  insensibly  lost.  Some  describe 
this  fascia  as  being  derived  from  the  intercolumnal 
bands.  Scarpa  considers  it  to  be  a  prolongation  of 
the  fascia  which  has  received  his  name.  It  is  so 
intimately  connected  with  all  these  structures,  that 
it  is  impossible  to  assign  it  to  any  distinct  origin.  It 
forms  the  third  covering  of  an  inguinal  hernia, 
whether  oblique  or  direct. 

On  dissecting  off  this  fascia,  the  external  abdominal 
ring  is  exposed.  This  may  be  now  seen  to  be,  as  al- 
ready described,  an  opening  in  the  external  oblique 
tendon,  formed  by  the  divergence  of  its  descending 
fibres;  it  transmits  the  spermatic  cord  in  the  male, 
the  ligamentum  teres  in  the  female.  It  is  triangular 
in  shape ;  the,  apex,  directed  upwards  and  outwards, 
and  rounded  off  by  the  intercolumnal  bands ;  its  base 
inferiorly  is  formed  by  the  crest  of  the  pubes;  its  in- 
ternal margin,  the  longest,  is  formed  by  the  internal 
pillar  of  the  ring,  its  external  margin  by  the  external 
pillar;  its  greatest  length  corresponds  to  that  of  its 
internal  margin,  and  varies  from  one  inch  to  one  inch 
and  a  half;  it  is  the  outer  or  anterior  opening  of  the  in- 
guinal or  spermatic  canal ;  through  it  an  inguinal 
hernia  emerges,  to  descend  into  the  scrotum. 

If  the  spermatic  cord  be  now  cut  across,  a  little 
beneath  the  ring,  and  gently  raised,  it  will  be  seen 
that  it  has  escaped  through  this  aperture,  resting  not 
on  the  bone,  but  on  the  external  pillar  of  the  ring, 
and  th,at,  behind  the  external  abdominal  ring,  some 
fibrous  structures  exist  which  assist  in  preventing  the 


84  THE   TRIANGULAR   LIGAMENT. 

protrusion  of  hernia  through  this  opening,  directly 
from  behind,  or,  in  other  words,  prevent  the  forma- 
tion of  a  direct  inguinal  hernia;  these  are  Colles's 
fascia,  and  the  conjoined  tendons. 

Colles's  fascia,  or  the  triangular  ligament  of  inguinal 
hernia,  is  liable  to  much  variety,  being  in  some  sub- 
jects well  marked,  in  others  altogether  wanting ;  it 
lies  behind  the  external  abdominal  ring,  in  front  of 
the  conjoined  tendons,  and  partially  concealed  by  the 
internal  pillar  of  the  ring.  It  is  formed  by  a  few 
fibres,  which  are  derived  from  the  posterior  surface 
of  the  external  oblique  tendon  of  the  opposite  side  ; 
the  ligaments  of  either  side,  therefore,  decussate.  Its 
base  is  implanted  into  the  crest  of  the  pubes ;  one 
margin  is  towards  the  linea  alba,  the  other  is  free, 
and  looks  upwards  and  outwards. 

The  conjoined  tendons  lie  behind,  and  to  the  outside 
of  the  preceding:  they  are  the  united  tendons  of  the 
internal  oblique  and  transversalis  muscles,  which  here 
pass  in  front  of  the  rectus  muscle ;  to  be  inserted  into 
the  upper  part  of  the  symphysis  and  crest  of  the  pubes; 
the  external  margin  of  the  conjoined  tendons  is  pro- 
longed beyond  the  outer  edge  of  the  rectus  muscle ;  it 
here  is  inferiorly  implanted  into  the  linea  innominata, 
where  it  is  continuous  with  Giinbernaut's  ligament. 
Above  this  the  transversalis  fascia  is  implanted  into 
it;  here,  indeed,  the  two  structures  frequently  ap- 
pear to  be  contiouous  one  with  the  other. 

From  the  great  strength  and  transverse  extent  of  the 
conjoined  tendons,  ancl  their  position  immediately  be- 
hind the  external  abdominal  ring,  they  contribute 
much  to  the  security  of  the  abdomen  in  this  situation, 
and  thus  prevent  the  formation  of  direct  inguinal  her- 
nia. 

The  inguinal  or  spermatic  canal  is  an  oblique  canal 
or  passage  between  the  abdominal  muscles,  which 
transmits  the  spermatic  cord  in  the  male,  the  liga- 
mentum  teres  in  the  female.  It  commences  at  the 
internal  abdominal  ring^  as  yet  concealed  from  view 


INGUINAL   CANAL.  85 

by  the  lower  margin  of  the  internal  oblique  muscle. 
This  is  an  opening  in  the  transversalis  fascia,  situated 
about  midway  between  the  spine  of  the  ilium  and  the 
symphysis  pubis,  but  somewhat  nearer  the  former, 
about  three-quarters  of  an  inch  above  Poupart's  liga- 
ment; from  this  the  canal  descends  forwards  and  in- 
wards between  the  oblique  muscles,  and  terminates  at 
the  external  abdominal  ring.  Its  length  is  about  one 
inch  and  a  half,  if  we  measure  the  distance  between 
the  two  nearest  points  of  the  two  rings ;  three  inches, 
if  we  measure  between  the  two  furthest  points  of  these 
openings,  and  two  and  a  half  inches,  if  we  measure 
between  the  intermediate  points. 

The  inguinal  canal  is  bounded,  above,  by  the  lower 
margins  of  the  internal  oblique  and  transversalis  mus- 
cles, below  by  Poupart's  ligament,  in  front  by  the  ex- 
ternal oblique  tendon  and  the  lower  margin  of  the  in- 
ternal oblique,  behind  by  the  transversalis  fascia,  the 
conjoined  tendons,  Colles'  ligament,  and  occasionally 
a  few  fibres  of  the  internal  oblique. 

The  superior  boundary  of  the  inguinal  canal  is 
formed  by  the  lower  margins  of  the  internal  oblique 
and  transversalis  muscles;  these  muscles  are  here  in- 
timately connected,  particularly  as  we  approach  the 
pubes— towards  the  ilium  theyare  partially  separated. 
Beneath  the  former,  the  spermatic  cord  may  be  seen 
to  emerge,  as  it  descends;  a  few  muscular  fibres  pass 
off  along  with  it,  which  form  the  cremaster  muscle. 
In  some  subjects  a  diiferent  arrangement  exists; 
which  is,  that  the  spermatic  cord  passes  out  between 
the  fibres  of  the  internal  oblique,  some  of  which  thus 
lying  beneath  the  cord,  this  structure  then  escapes 
through  a  perfectly  muscular  opening.  In  this  stage 
of  the  dissection,  the  extent  of  origin  of  the  internal 
oblique  muscle  from  Poupart's  ligament  maybe  ob- 
served ;  it  in  general  arises  from  the  external  two- 
thirds  and  upper  surface  of  the  ligament,  but  is  liable 
to  much  variety  in  this  respect ;  the  fibres  descend 
inwards  to  terminate  in  the  conjoined  tendons. 
8 


86     INTERNAL  ABDOMINAL  RING. 

The  cremaster  muscle  arises  not  only  from  the  lower 
margin  of  the  internal  oblique,  but  takes  a  few  fibres 
from  the  transversalis  muscle,  from  the  neighbouring 
surface  of  Poupart's  ligament,  and  from  the  pubes  a 
little  external  to  its  tubercle;  from  these  diiferent  ori- 
gins, its  fibres  descend  around  the  spermatic  cord,  but 
chiefly  on  its  outer  and  anterior  surface,  forming  a 
series  of  loops,  the  concavities  of  which  are  directed 
upwards,  and  are  finally  implanted  into  the  outer  sur- 
face of  the  tunica  vaginalis,  and  into  the  scrotum,  to 
the  lower  part  of  which  they  descend.  Between  the 
fibres  of  the  muscle,  the  spermaticus  supeficialis 
nerve,  a  branch  from  the  ilio-scrotal  descends,  to  be 
lost  in  the  coverings  of  the  testis. 

Poupart's  ligament  bounds  the  inguinal  canal  infe- 
riorly.  Near  the  internal  ring,  the  cord  is  about 
three-quarters  of  an  inch  above  Poupart's  ligament, 
but,  as  it  descends,  it  gradually  approaches  the  liga- 
ment, until  at  length  it  lies  imbedded  in  its  upper 
surface  which  is  grooved  for  its  protection. 

The  anterior  boundaries  of  the  inguinal  canal  have 
been  already  sufficiently  described.  It  &  posterior  walls 
are  the  fascia  transversalis  and  the  conjoined  tendons 
— this  latter  structure  forms  but  a  small  portion  of  tjie 
posterior  boundary  of  the  canal — it  lies  behind  the 
external  abdominal  ring.  The  transversalis  fascia  will 
be  better  seen  immediately. 

The  internal  abdominal  ring  is  formed  by  the  passage 
of  the  spermatic  cord  through  the  transversalis  fascia; 
as  the  cord  passes  through  the  fascia  it  draws  with 
it,  as  it  were,  a  cellular  prolongation  from  the  fascia; 
this  descends,  and  is  gradually  lost  upon  the  cord;  it 
is  named  thefasciapropria,  or  internal  spout-like  fascia. 
It  forms  the  fifth,  or  the  immediate  covering  of  the 
hernial  sac,  hence  its  name  of  fascia  propria.  It  is 
well  exposed  by  gently  drawing  downwards  the 
spermatic  cord. 

The  internal  abdominal  ring  is  a  little  nearer  the 
ilium  than  the  symphy  sis  pubis,  its  inner  margin  being 


MEASUREMENT   OF   PARTS.  87 

precisely  midway  between  these  two  points.     It  lies 
nearly  opposite  the  external  iliac  artery,  and  about 
one-half  to  three-quarters  of  an  inch  above  Poupart's 
ligament.     Directly  above  it  the  lower  fibres  of  the 
transversalis  muscle  cross  from  their  origin,  from  the 
external  third  or  half  of  Poupart's  ligament,  almost 
transversely  inwards,  to  become  identified  with  the 
internal  oblique  muscle,  and  implanted  with  it  into 
the  conjoined  tendons.    Occasionally,  as  Mr.  Guthrie 
has  described,  a  few  fibres  of  the  transversalis  muscle 
pass  behind  the  cord.    Along  the  internal  and  inferior 
part  of  the  internal  ring,  and  contained  in  the  trans- 
versalis fascia,  ascends  the  epigastric  artery. 

This  artery  arises  from  the  external  iliac,  a  little 
above  Poupart's  ligament;  it  at  first  descends,  then 
curves  upwards,  winding  around  the  cul  de  sac  of  the 
peritoneum,  and  then  ascends  inwards,  enters  the 
sheath  of  the  rectus  muscle,  and  terminates  by  anas- 
tomosing with  the  internal  mammary  artery.    It  lies 
about  a  quarter  of  an  inch  distant  from  the  cord. 

The  epigastric  artery  is  accompanied  by  one  or  two 
veins ;  if  by  one,  the  vein  lies  to  its  inner  or  pubal 
side;  if  by  two,  the  artery  lies  between  the  veins. 

The  following  measurements  of  the  parts   con- 
nected with  hernia  are  given  by  Sir  A.  Cooper. 

M.     r. 

'  anterior  superior  spinous  process  of  the  ins.  ins. 
ilium         .....    '5J     6 

tuberosity  of  the  pubes        .         .         .     l|     1  f 
inner  margin  of  the  lower  opening  of 

the  abdominal  canal .         .         .     OJ     1 
inner  edge  of  the  internal  abdominal  ring  3       3J 
to  the  middle  of  the  iliac  artery .         .     3_J    3| 
iliac  vein    .         .         .         .         .         .     2f     2J 

origin  of  the  epigastric  artery    .         .     3       3J 
course  of  the  epigastric  artery  on  the 
inner  side  of  the  internal  abdomi- 
nal ring    .         .         .         .         .     2f     2-J 

w  middle  of  lunated  edge  of  the  fascia  lata     3|    2  J 


88        '  TRANSVERSALIS   FASCIA. 

M.      F. 

From  the  anterior  edge  of  the  crural  arch  to  ins.  ins. 
the  saphena  vein  .         .  1       1J 

symphysis  pubis  to  the  middle  of 

the  crural  ring     .         .  2J     2| 

The  transversalis  fascia ;is  a  layer  of  condensed  cel- 
lular tissue  or  fascia,  situated  between  the  transver- 
salis muscle  and  the  peritoneum,  and  particularly 
well  marked,  inferiority,  where  the  internal  oblique  an  d 
transversalis  muscles  are  deficient. 

Superiorly,  the  transversalis  fascia  is  gradually  lost 
in  the  loose  cellular  tissue  which  connects  the  perito- 
neum on  its  anterior  and  posterior  surfaces  to  the  ab- 
dominal parietes,  but  inferiorly  becomes  strong  and 
well  marked.  Here,  on  the  outer  side,  it  is  attached 
to  the  inner  edge  of  the  crest  of  the  ilium,  more  in- 
ternally to  Poupart's  ligament,  behind  which  it  unites 
with  the  fascia  iliac  to  prevent  the  protrusion  of  hernia 
beneath  this  ligament ;  still  more  internally,  or  oppo- 
site the  fermoral  vessels,  it  descends  into  the  thigh, 
forming  the  anterior  layer  of  the  canal  in  which  these 
vessels  are  lodged;  still  nearer  the  pubis,  it  is  attached 
to  the  conjoined  tendons,  and  the  outer  edge  of  the 
rectus  muscle,  a  layer  of  it  passing  also  behind  this 
muscle  to  be  continuous  with  that  of  the  opposite  side. 

At  the  point  where  the  spermatic  cord  perforates 
the  transversalis  fascia,  namely,  the  internal  abdomi- 
nal ring,  the  fascia  frequently  presents  a  well-defined 
semilunar  border,  which  bounds  the  ring  to  its  inner 
Bide ;  in  other  cases  it  terminates  gradually  in  this  di- 
rection ;  in  all  instances  a  prolongation  is  derived 
from  it  which  descends  on  the  spermatic  cord,  and 
forms  the  fascia  propria,  or  fascia  spermatica,  of  Sir 
A.  Cooper.  Some  anatomists  describe  the  transver- 
salis fascia  as  being  composed  of  two  layers,  between 
which  the  epigastric  artery  ascends,|one  of  these  being 
attached  to  the  edge  of  the  rectus  muscle,  the  other 
passing  behind  the  muscle  to  the  opposite  side.  The 
transversalis  fascia  is  of  use  in  strengthening  the  ab- 


HERNIA   IN   FEMALE.  89 

dominal  parietes  inferiorly,  where  a  deficiency  exists 
in  the  internal  oblique  and  transversalis  muscles. 
From  its  connexion  with  the  transversalis  and  rectus 
muscles,  it  is  made  tense  by  the  action  of  these,  and 
is  thus  rendered  still  more  capable  of  opposing  the 
protrusion  of  a  hernia. 

As  the  hernia  is  first  protruded  against  the  inter- 
nal abdominal  ring,  it  pushes  before  it  the  peritoneum, 
which  forms  the  hernial  sac,  emerging  through  the 
ring  it  descends  in  front  of  the  spermatic  cord,  and 
here  receives  a  covering  from  the  fascia  propria;  de- 
scending still  further,  it  escapes  beneath  the  lower 
margin,  or  between  the  fibres  of  the  internal  oblique 
muscle,  here  it  enters  the  sheath  of  the  cremaster 
muscle,  and  continues  its  course  to  the  external  abdo- 
minal ring  ;  it  now,turning  forwards,  passes  through 
this  opening,  where  it  becomes  invested  by  the  exter- 
nal spout-like  fascia;  it  now  descends  into  the  scrotum, 
covered  still  further  by  Scarpa's  fascia,  the  superficial 
fascia,  and  the  integuments.  It  thus  is  covered  by 
the  integument,  the  superficial  fascia,  Scarpa's  fascia,  the 
external  spout-like  fascia,  the  sheath  of  the  cremaster 
muscle,  the  fascia  propria,  and  the  peritoneum,  forming 
the  hernial  sac. 

As  a  hernia  descends  into  the  scrotum,  beneath  the 
coverings  of  the  spermatic  cord,  it  finally  arrives  im- 
mediately above  the  testis,  in  which  position  it  is  re- 
tained by  the  attachment  of  the  spermatic  coverings 
to  the  upper  and  back  part  of  this  organ,  where  its 
vessels  and  nerves  enter. 

Now  the  principal  points  to  be  attended  to,  in  the 
anatomy  of  oblique  inguinal  hernia,  are — 1st,  its 
coverings;  2d,  the  part  of  the  canal  where  stricture 
most  frequently  occurs;  3d,  its  relation  to  the  epi- 
gastric artery,  to  the  spermatic  cord,  and  the  testis. 

Oblique  inguinal  hernia  in  the  female  occurs  much 
less  frequently  than  in  the  male,  owing  to  the  smaller 
size  of  the  inguinal  canal.  It  descends  into  the  labium 
8* 


90  DIRECT   INGUINAL    HERNIA. 

and  is  in  general  small.  It  is  almost  always  reducible. 
Should  it  become  strangulated,  the  operation  will  not 
differ  essentially  from  that  recommended  for  the 
male.  The  lower  part  of  the  peritoneal  bag,  accord- 
ing to  Sir  A.  Cooper,  contains  only  water.  The  in- 
cisions should  not  be  prolonged  much  into  the  labium. 

Direct  inguinal  hernia. — From  the  deficiency  in  the 
external  oblique  tendon,  described  in  oblique  inguinal 
hernia  under  the  name  of  the  external  abdominal 
ring,  it  follows  that  a  hernia  may  be  protruded  di- 
rectly forwards  from  the  abdomen  through  this  aper- 
ture, without  transversing  the  inguinal  canal ;  this 
will  therefore  form  the  direct  inguinal  hernia. 

Fortunately  nature  has  so  protected  this  opening 
posteriorly,  that  this  species  is  comparatively  rare. 
The  parts  that  oppose  its  formation  lie  behind  the 
ring ;  they  are,  the  triangular  ligament,  or  Colles' 
fascia,  the  conjoined  tendons,  the  edge  of  the  rectus 
muscle,  and  the  transversalis  fascia,  attached  to  the 
outer  edge  of  this  muscle  and  to  the  conjoined  ten- 
dons. 

These  barriers  are  not,  however,  in  all  cases  suffi- 
cient. As  a  direct  inguinal  hernia  makes  its  way 
forwards  through  the  external  ring  into  the  scrotum, 
it  pushes  before  it  the  peritoneum  which  forms  the 
hernia!  sac;  it  next  either  bursts  through,  or  carries 
with  it,  the  transversalis  fascia,  and  then  passing  to 
the  outer  edge  of  the  rectus  muscle  and  the  conjoined 
tendons,  it  escapes  through  the  external  ring,  and  is 
here  covered  by  the  external  spout-like  fascia,  the 
superficial  fascia,  and  the  integument.  It  is  evident 
that  the  hernia  can  receive  no  covering  (or  at  least  a 
very  partial  one)  from  the  cremaster  muscle,  nor  from 
the  fascia  propria  of  oblique  inguinal  hernia,  as  it 
does  not  descend  through  the  inguinal  canal.*  The 

*Sir  A.  Cooper  states  that  it  receives  a  covering  from  the  trana- 
versalis  tendon  and  fascia.  By  the  former  we  consider  him  to 
mean  an  expansion  from  the  transversalis  fascia,  where  it  is  at- 
tached to  the  conjoined  tendons. 


INGUINAL   POUCHES.  91 

epigastric  artery  lies  to  its  outer  side.  As  the  hernia 
emerges  from  the  external  ring,  it  lies  internal,  and 
a  little  posterior,  to  the  spermatic  cord. 

Direct  thus  differs  essentially  from  oblique  inguinal 
hernia  in  its  coverings,  and  in  its  relations  to  the  epi- 
gastric artery  and  spermatic  cord. 

If  we  examine  the  lower  part  of  the  parietes  of  the 
abdomen  on  their  inner  surface,  by  raising  the  in- 
testines from  the  cavity  of  the  pelvis,  leaving  the 
peritoneum  in  situ,  we  shall  there  see  two  depressions, 
or  fossse,  on  each  side,  which  seems  to  invite,  as  it 
were,  to  the  protrusion  of  a  hernial  tumour.  Between 
these  three  projecting  cords  maybe  noticed;  one  of 
these  is  situated  on  the  mesial  line,  and  is  formed  by 
the  urachus,  which  ascends  from  the  superior  fundus 
of  the  bladder  to  the  umbilicus;  the  remaining  two 
are  situated  one  on  each  side.  They  are  formed  by 
•the  degenerated  umbilical  arteries,  which  ascend  from 
the  lateral  surfaces  of  the  bladder,  converging  to  the 
umbilicus. 

These  depressions  are  named  the  internal  and  ex- 
ternal inguinal  fossse  or  pouches.  The  internal  inguinal 
fossa  lies  between  the  urachus  and  the  degenerated 
umbilical  artery,  the  first  of  which  separates  it  from 
its  fellow  of  the  opposite  side.  It  is  triangular  in 
shape,  the  base  inferiorly  being  formed  by  the  crest 
of  the  pubes.  It  lies  opposite  to  the  external  ring,  and 
thus  leads  to  the  formation  of  direct  inguinal  hernia. 

The  external  inguinal  fossa  lies  to  the  outer  side  of 
the  umbilical  artery ;  it  lies  superior  and  external  to 
the  other,  and  is  somewhat  larger;  it  leads  to  the 
internal  ring,  and  consequently  to  the  formation  of 
an  oblique  inguinal  hernia. 

The  projecting  cords,  formed  by  the  urachus  and 
umbilical  arteries,  contribute  more  to  the  formation  of 
hernia  than  the  inguinal  fossae ;  as  they,  when  the 
intestines  are  propelled  against  them  by  the  action  of 
the  abdominal  muscles,  give  to  the  propelling  force, 


92  FEMORAL   HERNIA. 

and  consequently  to  the  viscera,  a  direction  forwards 
towards  the  fossae. 

Femoral  hernia. — This  form  of  hernia  is  more  fre- 
quent in  the  female  than  in  the  male,  in  consequence 
of  the  greater  breadth  of  the  pelvis  in  the  former.  It 
is  sometimes  named  crural  hernia,  being  called  from 
its  making  its  appearance,  when  first  noticed,  in  the 
thigh ;  in  the  upper,  inner,  and  anterior  part  of 
which  region  it  descends  beneath  Poupart's  ligament, 
to  the  inner  side  of  the  femoral  vessels. 

Beneath  the  skin  is  the  superficial  fascia.  This  is 
fehe  common  subcutaneous  cellular  tissue  met  with  in 
every  part  of  the  body  beneath  the  integuments ;  it 
is  Here  well  marked,  and  is  frequently  loaded  with 
fat.  On  all  sides  it  is  continuous  with  the  surround- 
ing cellular  tissue.  Externally  a  few  transverse  fibres 
may  be  occasionally  met  with  in  it.  No  anatomist, 
so  far  as  we  are  aware  of,  has  as  yet  exercised  his 
ingenuity  in  the  vain-glorious  task  of  dividing  it  into 
any  definite  number  of  layers.  It  forms  the  most 
superficial  covering  of  the  femoral  hernia. 

In  the  superficial  fascia  we  notice  several  arteries, 
veins,  nerves,  and  lymphatic  glands.  The  arteries  are 
branches  of  the  external  circumflexa  ilii,  external  p^u- 
dic,  and  superficial  epigastric  arteries;  they  arise 
from  the  femoral  artery  a  little  below  Poupart's  lig- 
ament, perforate  the  cribriform  fascia,  and  are  lost 
in  the  superficial  fascia  and  integuments.  The  ex- 
ternal circumflexa  ilii  branches  pass  outwards  be- 
hind the  ilium;  the  external  pudic  to  the  organs  of 
generation;  whilst  the  superficial  epigastric  ascends 
inwards  over  Poupart's  ligament,  to  be  lost  in  the 
parietes  of  the  abdomen.  The  external  pudic  and 
superficial  epigastric  are  frequently  wounded  in  the 
operation  for  strangulated  femoral  hernia,  and  may 
require  the  ligature. 

The  veins  are  branches  from  the  surrounding  inte- 
guments, and  the  great  or  internal  saphena  vein.  This 
large  vein  commences  at  the  inner  side  of  the  foot  and 


FASCIA  LATA.  93 

leg,  ascends  along  the  internal  surface  of  the  thigh, 
curves  outwards  at  its  upper  part,  and  at  about  an 
inch  and  a  half  distance  from  Poupart's  ligament, 
perforates  the  cribriform  fascia,  through  the  sa- 
phenic  opening,  to  join  the  femoral  vein. 

In  some  cases  a  second  large  vein  ascends  along  the 
anterior  surface  of  the  thigh,  which  either  terminates 
in  the  saphena  or  in  the  femoral  vein.  In  operating 
for  strangulated  femoral  hernia,  as  well  as  in  other  ope- 
rations in  this  region,  the  saphena  vein  is  much  ex- 
posed. It  may  be  avoided  by  not  prolonging  our  in- 
cisions too  much  inwards.  Not  unfrequently  it  becomes 
varicose,  and  may  be  mistaken  for  a  femoral  hernia. 

The  nerves  met  with  in  the  superficial  fascia  are  small 
branches  derived  principally  from  the  anterior  crural. 

The  lymphatic  glands  compose  the  interior  set  of  in- 
guinal glands.  They  are  arranged  in  the  vertical  di- 
rection, and  consist  of  two  sets,  the  superficial  and 
deep.  The  superficial  are  three  or  four  in  number,  and 
are  enclosed  in  a  capsule  of  the  superficial  fascia.  The 
deep  are  two  or  three  in  number,  they  accompany  the 
femoral  vessels ;  one  is  almost  constantly  lodged  in 
the  femoral  ring. 

On  raising  the  superficial  fascia,  the  fascia  lata  is 
brought  into  view.  This  is  a  dense  layer  of  fibrous 
structure  which  invests  the  muscles  of  the  thigh. 
Inferiorly  it  is  attached  to  the  tendons  and  ligaments 
about  the  knee-joint;  from  this  it  ascends,  fbrming 
sheaths  for  the  different  muscles,  and  sending  in  pro- 
cesses between  them.  Having  arrived  at  the  upper  and 
anterior  part  of  the  thigh  ( where  it  is  connected  with 
the  anatomy  of  femoral  hernia,)  it  divides  into  three 
portions,  the  iliac,  pectineal,  and  cribriform  fa  seise. 

The  iliac  (so  called  from  its  connexionwith  the  os  ilii, ) 
or  external  portion  of  the  fascia  lata,  is  the  strongest; 
posteriorly  it  is  attached  to  the  crest  of  the  ilium ;  in 
front  we  find  it  closely  attached  to  the  lower  margin  of 
Poupart's  ligament.  As  we  trace  it  inwards  towards 
the  pubes,  it  terminates  in  an  elongated  process,  which 


94  PECTINEAL   FASCIA. 

passes  in  front  of  the  femoral  vessels,  gets  to  their 
inner  side,  and  is  implanted  into  the  front  of  the  pec- 
tineal  portion  of  the  fascia  lata.  Some  of  its  fibres  are 
here  reflected  behind  Poupart'sligament,  they  become 
'continuous  with  the  base  of  Gimbernaut's  ligament, 
and  are  inserted  with  it  into  the  ilio-pectineal  line. 
The  superior  edge  of  this  prolonged  portion  of  the 
fascia  lata  is  attached  to  Poupart's  ligament — its  infe- 
rior margin  is  free  and  concave,  the  concavity  looking 
downwards  and  inwards ;  this  portion  of  it  is  named 
Key's  ligament,  or  the  falciform  process  of  the  fascia 
lata,  whilst  its  point  of  attachment  to  the  pubic  por- 
tion of  the  fascia  lata  is  called  Colles'  ligament. 

A  short  distance  below  Key's  ligament  the  iliac 
portion  of  the  fascia  lata  is  gradually  prolonged  into 
the  cribriform  fascia,  but  not  unfrequently  presents,  in 
the  dissected  state,  a  well-defined  edge  at  the  outer 
side  of  the  femoral  artery.  Still  more  inferiority,  the 
iliac  portion  of  the  fascialatabecomes  continuous  wjth 
the  pectineal  portion  in  front  of  the  femoral  vessels  ; 
they  here  conjoined  form  a  well-defined  semilunar 
margin,  the  concavity  of  which  is  turned  up  wards,  and 
forms  Burns'  ligament.  This  margin  of  th  e  fascia  lata, 
on  a  careful  examination,  will  be  found  to  be  reflected 
backwards  on  the  anterior  surface  of  the  femoral  ves- 
sels, and  so  intimately  united  with  the  sheath,  as  to 
prevent  altogether  the  descent  of  a  hernia  beneath  it. 

The  pectineal  or  pubic  or  internal  portion  of  the  fascia 
lata  lies  in  front  of  the  pectineus  muscle — internally  it 
is  attached  to  the  symphysis  pubis,  where  it  lines  the 
gracilis  and  adductor  muscles;  as  we  trace  it  outwards 
it  passes  in  front  of  the  pectineus  muscle,  gets  behind 
the  femoral  vessels,  at  the  outer  edge  of  which  it  meets 
with  the  tendons  of  the  psoasmagnus  andiliacus  inter- 
ims muscles:  it  here  divides  into  two  laminae,  one  of 
which  passes  forwards,  to  be  attached  to  the  posterior 
surface  of  the  external  or  iliac  portion  of  the  fascia 
lata,  whilst  the  other  passes  backwards  to  be  attached 
to  the  capsular  ligament  of  the  hip-joint. 


CRIBRIFORM   FASCIA  95 

Superiorly  the  pectineal  fascia  ascends  in  front  of  the 
pectineus  muscle,  to  be  inserted  in  the  ilio-pectineal 
line,  where  it  becomes  continuous  with  the  fascia  ili- 
aca,  and  with  Gimbernaut's  ligament.  Inferiorly  it 
becomes  continuous  with  the  iliac  portion  of  the  fascia 
lata,  to  form  Burn's  ligament. 

Femoral  hernia,  as  it  descends,  rests  on  the  pecti- 
neal fascia.  Between  these  two  portions  of  the  fascia 
lata,  and  immediately  in  front  of  the  femoral  vessels, 
an  oval-shaped  space  exists,  which  is  covered  over  by 
a  thin  layer  of  cellular  substance,  named  the  cribriform 
fascia,  or  middle  portion  of  the  fascia  lata.  This  is  in 
general  described  as  a  process  of  the  fascia  lata,  with 
which  indeed  it  is  perfectly  continuous  at  the  circum- 
ference of  the  opening;  at  the  same  time,  it  is  so  inti- 
mately connected  to  the  superficial  fascia,  being  in  fact 
identified  with  it,  that  it  may  be,  with  equal  propriety, 
described  as  being  derived  from  this  fascia. 

The  cribriform  fascia  is  perforated,  as  its  name  im- 
plies, by  a  number  of  foramina,  which  transmit  nu- 
merous veins  and  nerves,  passing  between  the  super- 
ficial and  deeper  parts.  One  larger  than  the  rest  is 
formed  by  the  saphena  vein  dipping  in  to  join  the  fe- 
moral ;  this  is  the  saphenic  opening  ;  through  it  a  fe- 
moral hernia  most  frequently  passes  forward  beneath 
the  superficial  fascia ;  it  is  bounded  inferiorly  by 
Burn's  ligament.  From  the  little  resistance  the  cri- 
briform fascia  affords,  a  femoral  hernia  soon  makes 
its  way  through  it;  this  it  effects  either  by  bursting 
through  the  fascia,  or  dilating  one  of  the  openings  in 
it,  most  frequently  the  saphenic  opening. 

Having  examined  the  parts  on  the  anterior  surface 
of  the  thigh,  we  proceed  to  ascertain  by  what  means  a 
hernia  is  enabled  to  escape  from  the  cavity  of  the  ab- 
domen, so  as  to  descend  behind  the  fascia  lata.  For 
this  purpose  draw  the  peritoneum  and  viscera  out  of 
the  iliac  fossa,  and  examine  the  parts  which  descend 
beneath  Poupart's  ligament.  As  this  ligament  stretches 


$6  FASCIA   ILIACA. 

across  the  brim  of  the  pelvis,  (between  the  anterior 
superior  spinous  process  of  the  ilium  and  the  tubercle 
of  the  pubes)  it  leaves  a  large  space  (the  crural  arch) 
between  it  and  the  bone,  by  means  of  which  several 
structures  are  transmitted  from  the  pelvis  to  the  thigh, 
or  in  the  opposite  direction.  Thus  between  the  spine 
of  the  ilium,  the  inguino-cutaneous  nerve  descends, 
internal  to  this  the  psoas  magnus  and  iliacus  internus 
muscles,  and  between  them  the  anterior  crural  nerve, 
descend  in  a  deep  fossa  ;  still  more  internally  the  fe- 
moral vessels  pass.  On  the  inner  side  of  these  the 
absorbent  vessels  from  the  lower  extremity  ascend 
through  a  well-marked  opening  (the  femoral  ring.) 

So  many  parts  thus  passing  beneath  Poupart's  liga- 
ment, nearly  obliterate  the  space  between  it  and  the 
bone,  so  that  the  descent  of  a  femoral  hernia  is,  by 
these  means,  at  least  partially  prevented.  As,  how- 
ever, many  interstices  must  exist  between  these  parts, 
it  becomes  necessary  that  some  additional  structure 
should  exist,  in  order  to  preserve  the  integrity  of  the 
abdominal  cavity.  This  structure  does  exist,  and  is 
formed  by  the  junction  of  the  transversalis  fascia  and 
the  fascia  iliaca  behind  Poupart's  ligament. 

The  fascia  transversalis  descends  from  the  inguinal 
canal,  passes  backwards,  and  behind  Poupart's  liga- 
ment meets  with  the  fascia  iliaca. 

This  is  a  dense  layer  of  fascia,  which  invest  the  an- 
terior surface  of  the  iliacus  internus  muscle;  externally 
and  superiorly  it  is  firmly  attached  to  the  inner  lip  of 
the  crest  of  the  ilium.  Tracing  it  inwards,  it  lines  the 
muscle,  passes  behind  the  external  iliac  vessels,  send- 
ing off  at  the  same  time  an  expansion,  which  passes 
in  front  of  these  vessels,  binds  them  down,  and  forms 
the  fascia  propria  of  the  external  iliac  artery,  first  de- 
scribed by  Mr.  Abernethy.  At  the  inner  side  of  the 
iliac  vessels,  the  fascia  iliaca  becomes  attached  to  the 
ilio-pectineal  line,  whence  it  descends  into  the  pelvis, 
under  the  name  of  the  pelvic  fascia.  Near  the  pubes 


FEMORAL   RING.  97 

the  fascia  iliacabecomes  continuous  with  the  pectineal 
portion  of  the  fascia lata,  and  Gimbernaut's  ligament. 
Inferiorly,  or  towards  the  femoral  region,  the  fascia 
iliaca  curves  forwards,  and  meets  the  transversalis 
fascia  immediately  behind  Poupart's  ligament,  where 
the  two  fasciae,  united,  form  a  dense  whitish  tendinous 
line,  which  indicating  the  course  of  the  internal  cir- 
cumflexa  ilii  vessels,  extends  from  the  spine  of  the 
ilium  to  the  outer  edge  of  the  femoral  artery,  and  thus 
precludes  the  possibility  of  a  hernial  tumour  descend- 
ing between  these  points. 

At  the  outer  side  of  the  femoral  artery  the  fascia 
transversalis  and  the  fascia  iliaca  separate ;  the  fascia 
transversalis  descends  into  the  thigh  in  front  of  the 
femoral  vessels,  whilst  the  fascia  iliaca  descends  behind 
them,  thus  enclosing  these  vessels  in  a  distinct  well- 
marked  sheath.  This,  the  sheath  of  the  femoral  ves- 
sels, is  of  a  funnel  shape;  the  base  superiorly,  the 
apex  inferiorly,  is  gradually  lost  in  the  cellular  cover- 
ings of  the  femoral  vessels  in  the  thigh. 

The  femoral  artery  and  vein  are  not  in  close  contact 
whilst  contained  in  the  sheath,  but  are  separated  by  a 
septum  or  partition,  which  passes  from  its  anterior  to 
its  posterior  wall ;  and  which,  thus  opposing  the  sepa- 
ration of  these  walls,  prevents  the  descent  of  a  hernia 
between  the  femoral  vessels  and  the  fascia  transver- 
salis, or  anterior  wall  of  the  femoral  sheath.  In  ad- 
dition to  this,  the  fascia  transversalis  is  connected  by 
cellular  tissue  to  the  cellular  covering  of  the  vessels, 
so  as  to  assist  materially  in  preventing  a  descent  of 
a  hernia  in  this  direction. 

On  the  inner  side  of  the  femoral  vessels,  we  have 
just  stated  that  a  large  aperture  exists  for  the  trans- 
mission of  the  absorbent  vessels  from  the  lower  extre- 
mity. Here  the  provisions  against  the  descent  of  a 
hernial  tumour  are  but  trifling,  and  here  therefore  it 
is  that  a  femoral  hernia  first  makes  its  way  from  the 
cavity  of  the  abdomen.  This  opening  is  named  the 
9 


98  COURSE  OF  FEMORAL  HERNIA. 

femoral  ring,  and  should  be  attentively  studied.  It 
is  as  yet  concealed  from  view  by  a  delicate  layer  of 
cellular  tissue,  which  may  be  described  as  thelermi- 
nation  of  the  fascia  transversalis,  on  the  inner  side  of 
the  femoral  vessels.  This  forms  the  fascia  propria  or 
femoral  hernia,  inasmuch  as  a  hernial  sac,  protruding 
through  the  femoral  ring,  carries  the  fascia  before  it, 
and  thus  receives  from  it  an  immediate  investment  in 
a  fascia  propria.  Although  in  the  natural  state  the 
fascia  propria  is  thin  and  delicate,  yet  in  old  cases  of 
hernia  it  becomes  thickened  and  condensed,  so  as  to 
present  a  membranous  appearance.  In  some  cases 
it  may  be  burst  through,  so  that  no  fascia  propria  will 
then  exist.  Mr.  Guthrie  has  recorded  an  instance  of 
this. 

On  removing  the  fascia  propria,  the  femoral  ring 
will  be  at  once  exposed.  It  is  triangular  in  shape,  the 
base  externally  at  the  femoral  vein,  the  apex  internally 
at  Gimbernaut's  ligament;  it  is  bounded  in  front  by 
Poupart's  ligament,  and  the  reflected  portion  of  the 
falciform  process  of  the  fascia  lata.  behindby  the  hori- 
zontal ramus  of  the  pubes,  covered  by  the  pectineus 
muscle  and  the  pectineal  fascia.  The  spermatic  cord, 
or  ligamentum  teres,  lies  a  little  above  and  in  front  of 
it,  and  the  epigastric  artery  curves  to  its  outer  side. 
In  it  we  often  meet  with  a  lymphatic  gland. 

Here,  then,  is  the  unprotected  part  of  the  abdomen, 
through  which  a  femoral  hernia  descends  into  the 
thigh.  As  the  hernia  escapes  through  the  ring,  it 
pushes  before  it  the  peritoneum,  which  forms  the 
hernial  sac,  as  also  the  fascia  propria,  which,  together 
with  the  lymphatic  gland  in  the  ring,  affords  but  a 
feeble  resistance ;  the  latter  is  soon  pushed  aside,  the 
former  becomes  one  of  the  coverings  of  the  hernia, 
which,  descending  into  the  thigh  beneath  Poupart's 
ligament,  rests  on  the  pectineal  fascia,  behind  the  fal- 
ciform process  of  the  fascia  lata.  It  soon  arrives  op- 
posite the  cribriform  fascia.  Its  further  descent  is 


OBTURATOR   HERNIA.  99 

prevented  by  the  convexity  of  the  saphena  vein,  by 
the  attachment  of  Burn's  ligament  to  the  front  of  the 
femoral  vessels,  and  by  the  motions  of  the  thigh  on 
the  pelvis.  Meeting  with  little  resistance  from  the 
cribriform  fascia,  it  changes  its  course,  turns  for- 
wards, bursting  through  the  fascia,  or  dilating  one  of 
the  apertures  in  it,  most  frequently  the  saphenic  open- 
ing, and  lies  beneath  the  superficial  fascia". .  It  soon 
changes  its  course  a  second  time ;  it  now  turns  up- 
wards, ascends  over  Poupart's  ligament,  and  finally 
rests  above  this  ligament,  on  Scarpia's  fascia  of  in- 
guinal hernia,  which  alone  separates  it  from  the  ten- 
don of  the  external  oblique  muscle.  It  is  here  then 
covered  by  the  integument,  superficial  fascia,  fascia  pro- 
priay  and  hernial  sac. 

We  have  stated  that  the  femoral  ring  is  bounded 
internally  by  Gimbernaut's  ligament.  This  is  the  third 
insertion  of  Poupart's  ligament,  from  the  pubic  ex- 
tremity of  which  it  extends  obliquely  inwards  and 
backwards,  to  be  inserted  in  the  ilio-pectineal  line  ; 
it  is  triangular  in  shape,  the  apex  turned  inwards  to- 
wards the  pubes ;  it  base  is  directed  outwards,  is  se- 
milunar,  and  forms  the  inner  boundary  of  the  femo- 
ral ring ;  one  edge  is  turned  forwards,  and  is  attached 
to  Poupart's  ligament;  the  other  is  directed  back- 
wards and  inwards,  and  is  implanted  into  the  ilio- 
pectineal  line.  Gimbernaut's  ligament  is  of  use  in 
preventing  the  descent  of  a  femoral  hernia  on  the 
inner  side  of  the  femoral  ring. 

The  femoral  ring  possesses  in  many  subjects  a  re- 
lation which  should  not  be  overlooked;  it  is  the 
obturator  artery.  This  vessel  in  general  arises  from 
the  internal  iliac  artery.  Where  this  is  the  case,  it 
can  have  no  relation  to  a  femoral  hernia ;  but  in 
numerous  instances  it  will  be  found  to  arise  from 
the  epigastric,  close  to  the  origin  of  this  vessel  from 
the  external  iliac  artery. 

Now  as  its  ultimate  distribution  is  to  the  parts  in 


100  THE    KIDNEYS. 

the  neighborhood  of  the  obturator  foramen,-  it  ne- 
cessarily follows,  when  such  is  its  origin,  that  in 
order  to  arrive  at  this  foramen,  it  must  cross  the 
femoral  ring,  and  consequently  a  femoral  hernia,  if 
such  should  exist.  As  it  proceeds  to  the  foramen, 
it  may  either  pass  directly  to  it  along  the  outer  side 
of  the  neck  of  the  hernia ;  or  it  may  first  pass  along 
its  posterior  surface,  and  then  enter  the  foramen: 
or  it  may  wind  along  the  anterior  surface  of  the 
neck  of  the  sac,  and  then  descend  to  the  inner  side. 

SECTION  V. 

The  Urinary  Organs. 

These  organs  consist  of  the  kidneys,  ureters,  blad- 
der, and  urethra. 

The  KIDNEYS  are  situated  one  on  each  side,  in  the 
right  and  left  lumbar  regions,  behind  the  colon,  in 
front  of  the  quadratus  lumborum  muse.,  and  corre- 
spond to  the  last  two  dorsal  and  first  two  lumbar  ver- 
tebrae, reaching  from  the  last  rib  to  the  crest  of  the 
ilium;  the  anterior  surface  is  convex,  the  posterior 
flattened ;  their  extremities  are  convex,  the  upper 
being  a  little  the  larger,  the  ext.  margin  is  convex, 
the  int.  concave  and  notched  for  the  passage  of  the 
vessels  and  ureters ;  the  right  touches  the  liver 
superiorly,  the  caecum  inferiorly ;  the  left  the  spleen 
above,  the  sigmoid  flexure  of  the  colon  below;  each 
kidney  is  surmounted  by  the  suprarenal  capsule. 
The  kidney  has  but  one  coat,  the  fibrous;  it  is 
strong  and  well  marked. 

The  internal  structure  of  the  kidney  is  composed  of 
the  secretory  or  cortical  substance,  and  the  excretory 
or  tubular  portion.  The  secretory  or  cortical  substance 
forms  its  greater  portion  and  occupies  its  outer  part; 
it  is  arranged  in  conical  masses,  the  cones,  about  fif- 
teen in  number,  which  terminate  in  pointed  extremi- 


SUPRARENAL   CAPSULES.  101 

ties,  the  mammillary  processes  ;  these  are  about  twelve 
or  thirteen  in  number,  and  are  surrounded  by  the 
calyces. 

The  tubuli  uriniferi  proceed  from  the  cortical  sub- 
stance, to  which  they  give  a  striated  appearance; 
they  open  on  the  mammillary  processes. 

The  calyces,  s>x  or-e^gVi;  in  number,  ftyrm  conical 
cups,  into  which '%e  ur^ne  i£  dropped  from  the  mam- 
millary processes ;.  they  unite  into  three  tubes,  the  in- 
fundibula,  wkich  Uiutingforor;'  a  'f  am  oil-shaped  tube, 
the  pelvis  of  tne  kidrfey  :  this  te?ihmht3S  in  iue  ureter. 

Each  kidney  is  supplied  with 'blood  from  the  renal 
art.;  the  right  is  larger  than  the  left,  its  blood  is 
returned  by  the  renal  vein,  which  opens  on  each  side 
into  the  inf.  vena  cava.  Its  nerves  are  derived  from 
the  renal  plexus  formed  from  the  lesser  splanchnic, 
sympathetic,  and  solar  plexus. 

The  ureter,  the  excretory  duct  of  the  kidney,  pro- 
ceeds from  the  pelvis  of  the  kidney  downwards  and 
inwards,  across  the  psoas  muse.,  and  iliac  art.  and 
behind  the  peritoneum ;  it  then  sinks  backwards  into 
the  pelvis,  turns  forwards,  and  comes  in  contact 
with  the  inferior  surface  of  the  bladder ;  it  runs 
forwards  and  inwards  between  the  muscular  and 
mucous  coats  of  this  viscus  for  a  short  distance,  and 
finally  opens  into  it  at  the  posterior  angle  of  the  tri- 
gone  vesicale.  The  ureter  is  crossed  superiprly  by 
the  spermatic  vessels,  near  its  termination  by  the  vas 
deferens  in  the  male,  and  by  the  Fallopian  tube  and 
broad  ligament  in  the  female.  The  ureter  is  com- 
posed of  nbro-mucous  membrane  ;  the  fibrous  coat 
is  well  marked,  its  cavity  is  smallest  at  its  termina- 
tion, largest  at  its  commencement. 

The  suprarenal  capsules  "are  two  yellowish  bodies 
placed  on  the  upper  ext.  of  each  kidney ;  they  are 
largest  in  the  foetus,  at  which  period  they  exceed 
the  kidneys  in  size ;  they  degenerate  into  cellular 
tissue  in  the  adult. 

9* 


102  STRUCTURE   OP  BLADDER. 

The  bladder  is  lodged  in  the  cavity  of  the  pelvis, 
behind  the  pubes,  in  front  of  and  above  the  rectum, 
and  between  the  levatores  ani  muscles ;  pyramidal 
in  shape,  its  apex  rounded,  is  directed  upwards  and 
forwards,  its  base,  directed  downwards  and  back- 
wards, rests  on  the  lower  extremity  of  the  rectum, 
from  whieli  it  i.s  separated  'by  the?  prostate  gland,  ves- 
iculse  scrambles,  and  vass,  cteferentia:  its  anterior 
surface,  somewhat  flattened,  is  in  contact  with  the 
pubes,  its  posterior  with  the  recttfin  and  small  intes- 
tines. ID  t'ie  female  the  uterus  intervenes  between 
the  bladder  and  rectum. 

The  bladder  is  composed  of  four  coats,  serous,  mus- 
cular, fibrous,  and  mucous ;  the  serous  coat  is  derived 
from  the  peritoneum,  it  is  only  a  partial  covering; 
the  parts  covered  are  the  posterior  half  of  superior 
fundus  or  apex,  the  posterior  surface  and  the  ante- 
rior portion  of  the  lateral  surfaces,  the  rest  is  un- 
covered by  peritoneum;  the  muscular  coat  consists 
of  three  sets  of  fibres ;  the  longitudinal,  best  marked, 
are  situated  on  the  anterior  and  posterior  surfaces, 
they  unite  at  the  superior  fundus  at  the  attachment 
of  the  urachus,  and  inferiorly  are  lost  in  the  neck  of 
the  bladder;  the  oblique  fibres  are  best  marked  pn 
the  lateral  surfaces,  the  circular  surround  the  neck 
of  the  bladder. 

The  fibrous  coat  of  the  bladder  is  well  marked;  the 
mucous  coat  lines  the  interior,  it  is  of  an  irregular 
pinkish  colour,  and  is  generally  thrown  into  folds  in 
the  collapsed  state ;  on  it  may  be  observed  the  orifices 
of  the  ureters ;  immediately  behind  the  neck  of  the 
bladder  is  a  triangular  space,  pale  and  smooth,  the 
trig  one  vesicale;  its  apex  is  at  the  orifice  of  the  uretha, 
its  base  is  formed  by  a  line  drawn  from  the  orifice  of 
one  ureter  to  that  of  the  other,  its  sides  formed  by 
lines  drawn  from  them  forwards  to  the  apex,  beneath 
them  some  muscular  fibres  are  described.  The  liga- 
ments of  the  bladder  are  the  false  and  true ;  the  false 
are  folds  of  the  peritoneum,  and  are  five  in  number, 


THE   URETHRA.  103 

viz.,  two  posterior,  two  lateral,  and  one  anterior; 
the  true  are  folds  of  the  pelvic  fascia,  and  are  four 
in  number,  viz.,  two  lateral,  which  pass  off  from  the 
inner  surface  of  the  levator  ani  on  the  lateral  surface 
of  the  bladder,  and  two  anterior,  which  run  from  the 
neck  to  the  back  of  the  os  pubis. 

The  bladder  is  supplied  with  blood  chiefly  by  the 
vesical  branches  of  the  int.  iliac,  its  nerves  are  de- 
rived from  the  hypogastric  plexus,  and  consists  of 
spinal  and  sympathetic  filaments. 

The  urethra  extends  from  the  neck  of  the  bladder 
to  the  orifice  on  the  glans  penis,  about  nine  inches  in 
length,  it  is  divided  into  three  portions,  the  prostate, 
membranous,  and  spongy.  The  prostatic  portion  is 
surrounded  by  the  prostate  gland ;  about  an  inch  and 
a  half  in  length,  it  runs  downwards  and  forwards,  its 
cavity  is  wider  in  the  centre  than  at  its  extremities ; 
on  its  lower  surface  is  a  projection  of  the  mucous 
membrane,  the  caput  gallinaginis  or  verumontanum,  on 
the  anterior  margin  of  this  is  a  depression,  the  sinus 
pocularis,  and  on  each  side  of  this  a  small  orifice,  the 
opening  of  the  common  ejaculatory  duct,  at  the  side 
of  the  verumontanum  is  a  fossa,  the  prostatic  sinus,  on 
which  a  number  of  the  prostatic  ducts  open. 

The  membranous  portion  of  the  urethra  lies  imme- 
diately beneath  the  sub-pubic  arch,  from  which  it  is 
separated  by  the  sub- pubic  ligament,  the  dorsal  veins 
of  the  penis,  and  the  apex  of  the  triangular  ligament ; 
about  three-quarters  of  an  inch  in  length,  it  is  slightly 
curved;  its  cavity  is  smooth  and  small  in  size,  its 
external  covering  is  a  dense  fibrous  membrane.  The 
spongy  portion  of  the  urethra  is  that  surrounded  by 
the  corpus  spongiosum  urethrse,  it  forms  the  remain- 
der of  the  canal;  it  commences  posteriorly  by  a  small 
dilatation,  the  sinus  of  the  bulb,  and  terminates  at  the 
ext.  orifice,  the  spongy  portion  dilates  a  little  again 
behind  the  orifice  forming  the  fossa  navicularis,  and 
then  contracts  to  form  the  orifice — a  slit-like  aperture 


104  THE  TESTES. 

on  the  glans  penis.  In  the  interior  of  this  portion 
of  the  canal  are  numerous  lacunae,  one  larger  than 
the  rest,  locuna  mayna,  is  situated  near  the  fossa  na- 
vicularis.  The  urethra  in  the  female  is  short,  about 
one  inch  and  a-half  in  length,  and  opens  externally 
beneath  the  clitoris  between  the  nymphae  minores, 
and  immediately  above  the  orifice  of  the  vagina. 

SECTION  VI. 
Male  Organs  of  Generation. 

These  consist  of  the  testes,  vasa  deferentia,  vesi- 
culse  seminales,  and  penis. 

The  testes  are  enclosed  after  birth  in  the  scrotum, 
before  this  period  they  are  placed  a  little  beneath  the 
kidneys,  whence  they  descend  into  the  scrotum. 

The  scrotum  is  formed  by  a  continuation  of  the  com- 
mon skin,  the  dartos,  superficial  fascia,  tunica  corn- 
munis  and  tunica  vaginalis.  The  skin  of  the  scrotum 
is  of  a  darkish  brown  and  corrugated ;  it  presents  on 
the  mesial  line  the  raphe ;  the  dartos  is  a  thin  layer 
of  muscular  fibres  seldom  well  marked ;  the  superfi- 
cial fascia  is  continuous  with  that  of  the  surrounding 
parts,  it  contains  no  adipose  substance ;  the  tunica 
communis  is'a  layer  of  fibrous  membrane  derived  su- 
periorly from  the  cremaster  muscle,  and  continuous 
with  the  fascia  investing  the  spermatic  cord  above; 
the  tunica  vaginalis  is  that  layer  of  this  membrane 
which  passes  from  off  the  testis  to  the  inner  surface 
of  the  scrotum ;  it  thus  forms  a  smooth  cavity  in  which 
the  testis  is  lodged.  The  scrotal  or  testal  cavity  on 
each  side  is  distinct  from  the  opposite  one,  being  se- 
parated by  the  septum scroti,  which  is  formed  by  are- 
flection  inwards  of  the  dartos,  and  the  superficial 
fascia. 

The  testes  are  contained  in  the  scrotal  cavities. 
Each  testis  is  of  an  oval  shape,  the  long  axis  being 
directed  downward,  backwards,  and  a  little  inwards, 
the  outer  surface  is  convex,  the  inner  somewhat  flat- 


VAS   DEFERENS.  105 

tened,  the  lower  extremity  is  the  smaller,  the  upper 
is  capped  by  the  head  of  the  epididymis.  It  is  com- 
posed of  three  coats,  a  serous,  fibrous,  and  vascular. 
The  serous  coat  is  a  portion  of  the  tunica  vaginalis ; 
this,  originally  a  reflexion  of  the  peritoneum,  forms  in 
the  adult  a  distinct  shut  sac,  lining  the  inner  surface 
of  the  scrotum  (tunica  vag.  scroti)  and  the  outer  sur- 
face of  the  testis  (tunica  vag.  testis;)  it  is  partial, 
and  does  not  cover  the  testis  on  its  back  part,  where 
the  epididymis  is  attached  and  the  vessels  enter. 

The  fibrous  coat  is  the  tunica  albuginea.  It  is  very 
dense,  and  of  a  whitish  colour,  the  fibres  interlace 
with  each  other,  and  send  processes  through  the  sub- 
stance of  the  testis,  which,  as  they  pass  backwards, 
form  an  imperfect  septum,  mediastinum  testis,  and 
terminate  in  and  form  the  corpus  Highmorianum. 

Tunica  vasculosa  lines  the  internal  surface  of  the 
preceding ;  it  is  formed  by  a  delicate  network  of 
vessels. 

The  proper  substance  of  the  testis  consists  of  an  in- 
finite number  of  small  tubes,  tubuli  seminiferi,  which 
form  a  grayish  pulpy  mass ;  they  terminate  in  about 
twenty  larger  vessels  which  take  a  straight  course, 
hence  called  tubuli  recti,  towards  the  back  part  of  the 
testis ;  they  here  form  a  network  with  the  vessels  and 
nerves  of  the  testis  forming  the  rete  testis,  lying  be- 
tween the  layers  of  the  mediastinum  testis ;  from  the 
upper  and  back  part  of  this  eight  or  ten  vessels  pro- 
ceed, called  vasa  efferentia,  or  coni  vasculosi,  and  ter- 
minate in  the  head  of  the  epididymis,  forming  one 
tube,  the  vas  deferens;  this  is  convoluted  in  a  remark- 
able manner,  and  forms  the  epididymus ;  this  emerges 
from  the  globus  minor,  ascends  along  the  inner  edge 
of  the  epididymis,  and  forms  part  of  the  spermatic 
cords.  The  vas  deferens  ascends  with  this,  passes 
along  the  inguinal  canal,  winds  inwards  at  the  inter- 
nal abd.  ring,  and  then  descends  into  the  pelvis  to  the 
inner  side  of  the  hpyogastric  art.  and  ureter,  and 


106  THE   PROSTATE   GLAND. 

reaches  the  inferior  fundus  of  the  bladder;  it  here 
runs  forwards  and  inwards  along  the  inner  side  of 
the  vesicula  seminalis,  perforates  the  prostate  gland 
and  unites  with  the  duct  of  the  vesicula  seminalis  to 
form  the  common  ejaculatory  duct,  and  terminates  on 
the  verumontanum ;  the  vas  deferens  lies  on  the  pos- 
terior part  of  the  cord,  where  it  may  be  distinguished 
by  its  whipcord-like  feel.  Its  structure  is  fibro- 
mucous ;  the  fibrous  coat  is  very  dense ;  the  canal  is 
extremely  small,  being  not  larger  than  a  bristle. 

The  spermatic  cord  is  formed  of  the  vas  deferens, 
the  spermatic  art.,  veins,  and  nerves;  it  extends 
from  the  epididymis  to  the  int.  ring,  where  its  com- 
ponent parts  separate.  The  vas  deferens  proceeds 
as  described.  The  spermatic  art.  ascends  to  its  origin 
from  the  renal,  the  veins  to  the  renal  veins,  and  the 
nerves  to  the  renal  plexus  and  sympathetic  nerve. 
The  coverings  of  the  cord  have  been  described  with 
hernia,  the  remains  of  the  peritoneum  covering  the 
cord  are  sometimes  described  as  the  tunica  vaginalis 
of  the  cord. 

The  vesiculse  seminales  are  situated  6ne  on  each  side 
of  the  inferior  fundus  of  the  bladder  to  the  outer 
side  of  the  vas  deferens;  pyriform  in  shape,  the 
larger  extremity  is  directed  backwards  and  outwards , 
the  smaller  forwards  and  inwards,  terminates  in  a 
small  duct  which  unites  with  the  vas  deferens,  and 
terminates  with  it  as  just  described.  The  structure 
of  the  VQsiculae  seminales  is  fibro-mucous,  its  interior 
presenting  a  number  of  cells,  with  a  central  longitu- 
dinal canal. 

The  prostate  gland  surrounds  the  neck  of  the  blad- 
der and  first  portion  of  the  urethra,  which  passes  near 
to  its  upper  surface,  one-third  of  the  gland  being 
above,  and  two-thirds  beneath  this  canal.  The  pros- 
tate gland  is  covered  by  the  ascending  layer  of  the  tri- 
angular ligament  of  the  urethra,  and  has  attached  to 


GLANS   PENIS.  107 

it  anteriorly  the  anterior  true  ligaments  of  the  blad- 
der which  connect  it  to  the  pubic  arch. 

The  prostate  gland  is  chestnut-shaped,  the  base 
posteriorly,  the  apex  anteriorly ;  it  consists  of  three 
lobes,  two  lateral  and  a  middle  lobe  ;  the  lateral  are 
separated  by  a  slight  depression  on  its  under  sur- 
face, the  middle  lobe  lies  in  and  a  little  above  the 
centre  of  the  sulcus  at  its  posterior  extremity.  This 
gland  is  composed  of  a  number  of  mucous  follicles,  its 
ducts  open  into  the  prostatic  portion  of  the  urethra, 
the  greater  number  on  the  sinus  poculosus. 

The  penis  arises  by  two  roots,  the  crura  penis,  one 
on  each  side,  from  the  rami  of  the  ischium  and 
pubes ;  these  are  conical  in  shape,  pass  forwards, 
converging,  and  unite  to  form  the  corpus  cavernosum 
penis,  which  forms  the  body  of  the  penis  as  far  for- 
wards as  the  glans:  as  the  corpus  cavernosum  is 
partially  divided  by  an  imperfect  septum,  it  may  be 
considered  as  consisting  of  two  lateral  portions. 
This  body  is  covered  exteriorly  by  a  dense  fibrous 
structure,  which  forms  the  septum,  within  which  is 
a  peculiar  erectile  tissue  composed  chiefly  of  ar- 
teries. The  penis  presents  on  its  upper  surface  a 
slight  depression,  in  which  are  lodged  the  dorsal 
vessels  and  nerves  ;  on  its  under  surface  is  a  larger 
depression,  giving  lodgement  to  the  corpus  spongio- 
sum  urethrae ;  it  is  covered  by  a  delicate  thin  skin, 
which  anteriorly  forms  the  prepuce,  connected  to  the 
under  surface  of  the  glans  by  the  frsenum  preputii; 
where  this  is  reflected  on  the  corona  glandis,  a  num- 
ber of  sebaceous  follicles,  glandulse  Tysoni,  are  found. 

The  glans  penis  is  formed  altogether  by  the  corpus 
spongiosum  urethrae.  The  penis  is  supplied  with 
blood  by  its  dorsal  and  cavernous  vessels ;  branches 
of  the  int.  pubic;  its  veins  pass  backward  beneath 
the  sub-pubic  arch,  and  form  a  network  around  the 
prostate  gland,  and  terminate  in  the  int.  iliac ;  its 
nerves  are  derived  from  the  int.  pubic.  The  corpus 


108  MUSCLES  OF  THE  PERINEUM. 

spongiosum  is  supplied  by  the  the  art.  of  the  bulb, 
a  branch  also  of  the  int.  pubic  :  its  structure  is  also 
erectile,  and  seems  to  be  chiefly  composed  of  veins. 

SECTION   VII. 

The  PerinsBum 

is  a  diamond-shaped  space  situated  between  the 
thighs  on  each  side,  the  scrotum  and  sub-pubic  an- 
gle in  front,  and  the  os  coccygis  behind.  In  this  is 
included  the'  anal  region,  properly  so  called,  which 
occupies  the  posterior  triangle,  whilst  the  proper 
periuaeum  occupies  the  anterior.  The  lateral  boun- 
daries of  the  perinasum  are  on  each  side  the  rami  of 
the  ischium  and  pubes,  the  tuber  ischii,  and  the 
edge  of  the  glutseus  maximus  muscle,  and,  more 
deeply,  the  great  sacrosciatic  ligament. 

The  integuments  of  this  region  are  thin,  of  a 
brownish  color,  and  present  on  the  mesial  line  a 
fold  termed  the  raphe.  This  commences  at  the  anus, 
and  may  be  traced  as  far  forwards  along  the  mesial 
line  of  the  scrotum  as  the  root  of  the  penis.  Be- 
neath the  integuments  is  a  quantity  of  loose  cellular 
tissue,  the  superficial  fascia  of  the  perinaeum,  con- 
tinuous on  either  side  with  the  superficial  fascia  of 
the  thighs,  in  front  with  that  of  the  scrotum,  and 
posteriorly  with  the  adipose  tissue  filling  up  the 
large  space  at  the  side  of  the  rectum. 

Beneath  the  superficial  fascia  is  the  perinxal  fascia; 
this  is  much  more  dense  than  the  preceding,  and  is 
firmly  attached  on  each  side  to  the  rami  of  the  ischium 
and  pubes ;  anteriorly  it  is  lost  on  the  scrotum,  and 
posteriorly  is  continuous  with  the  adipose  tissue 
surrounding  the  rectum.  Beneath  this  lie 

The  Muscles  of  the  Perinseum. 
Transversus  Perinsei. — Or.  from  the  inner  surface 
of  the   tuber,  ischii,  above   the   erector  penis  m. 


DEEP   PERIN^AL   FASCIA.  109 

Ins.  into  the  central  point  between  the  accelerator 
urinae  and  sphincter  ani  m.  .-.  these  two  muscles 
correspond  to  the  transverse  line  just  referred  to .  •. 
one  or  two  more  m.  (T.  P.  Alteri)  sometimes  pass 
upwards  and  inwards  to  the  accelerator  urinae  m. 
Use,  to  fix  the  central  point  of  the  perinaeum. 

Accelerator  urinse. — Or.  1,  the  central  point  and  two 
inches  of  the  fibrous  raphe*  running  from  it  along 
the  corpus  spong. ;  2,  from  the  post,  part  of  the  tri- 
angular ligament.  Ins.  1,  the  posterior  fibres  into 
the  inner  side  of  the  crus  penis;  2,  the  middle  by 
distinct  aponeurotic  fibres  into  the  groove  between 
the  two  corp.  cavernosa,  commencing  at  the  junction 
of  the  two  crura ;  8,  the  anterior  pass  upwards  and 
forwards  over  the  corp.  cavern.,  and  are  ins.  into  the 
suspensor  lig.  of  the  penis.-.  The  ant.  fibres  com- 
press the  dorsal  veins  of  the  penis.  (Houston.) 
Use,  to  compress  the  bulb  and  corpus  spongiosum 
urethrae,  and  to  expel  their  contents,  whether  urine 
or  semen ;  hence  called  ejaculatores  seminis. 

Erector  penis — Or.  1,  fleshy  and  tendinous  from  the 
inner  edge  of  the  tuberosity  of  the  ischium,  and  root 
of  the  crus  penis.  Ins.  by  a  tendinous  expansion  into 
the  fibrous  membrane  of  the  corpus  cavernosum. 
Use,  to  erect  the  penis  by  forcing  the  blood  forwards. 

The  whole  of  these  muscles  being  removed,  the 
crura  penis  detached,  and  the  urethra  cut  through  in 
front  of  the  bulb,  and  reflected  backwards,  the  deep 
perinseal  faschia  or  triangular  ligament  of  the  urethra 
is  exposed.  This  is  a  dense  fibrous  layer  closing  up 
the  anterior  triangle  of  the  perinaeum.  On  each  side 
it  is  firmly  attached  to  the  rami  of  the  ischium  and 
pubes,  and  tuber  ischii,  and  is  here  continuous  with 
the  outer  layer  of  the  pelvic  fascia.  Its  apex,  turned 
forwards,  passes  above  the  urethra,  splits  into  two 
layers,  enclosing  the  sub-pubic  ligament,  and  lost  on 
the  surface  of  the  pubes ;  its  base,  turned  backwards, 

10 


110  MUSCLES  OF  PERINEUM. 

is  crescentic  to  accommodate  the  concavity  of  the 
rectum,  and  is  lost  on  tUe  surfaces  of  this  intestine. 

The  triangular  lig.  is  perforated  near  the  centre 
by  the  memb.  portion  of  the  urethra,  which  passes 
through  it  from  above  downwards  and  forwards. 
As  the  urethra  passes  through,  the  ligament  sends 
off  two  layers,  the  ascending  and  descending.  The 
ascending  passes  upwards  and  backwards,  and  is  lost 
on  the  capsule  of  the  prostate  gland ;  the  descending 
passes  downwards  and  forwards,  and  is  lost  on  the 
fibrous  covering  of  the  corpus  spongiosum  urethrse. 
In  the  angle  between  this  and  the  bulb  lie  two  small 
glands,  Cowper'z  glands,  which  open  by  small  ducts 
on  the  interior  of  the  bulb. 

The  posterior  triangle  of  the  perinseum  is  occupied 
by  the  anus  and  lower  ext.  of  the  rectum.  Around 
the  anus  is  the 

Sphincter  ani  muscle. — Or.  from  the  extremity  of 
the  coccyx;  its  fibres  surround  the  anus,  and  are 
Ins.  into  the  central  point  of  the  perinaeum.  Use, 
to  close  the  anus. 

At  each  side  of  the  rectum  is  a  large  space  occu- 
pied by  a  quantity  of  adipose  tissue ;  on  removing 
this,  the  following  muscle  is  exposed— 

Levator  ani. — Or.  1,  from  the  posterior  part  of  the 
symphysis  pubis,  below  the  true  ligaments  of  the  blad- 
der;  2,  from  the  obturator  fascia,  and  from  the  ilium 
above  the  thyroid  foramen,  by  means  of  the  pelvic 
fascia;  3,  from  the  inner  surface  and  spine  of  the 
ischium,  the  fires  converge,  and  are  Ins.,  the  anterior 
fibres  into  the  central  point  of  the  perinseum  and  fore 
part  of  the  rectum,  the  middle  into  the  side  of  the 
rectum,  the  posterior  into  the  back  part  of  the  rec- 
tum and  the  sides  of  the  os  coccygis.  Use,  to  raise 
and  draw  forwards  the  lower  ext.  of  the  rectum ;  also 
to  assist  the  expulsion  of  the  urine  and  semen. 

The  anterior  fibres  of  this  muscle  are  sometime* 


NYMPHS.  Ill 

described  as  Wilson's  muscles  ;  a  few  of  its  fibres  are 
also  described  as  Guthries  muscles. 

Behind  the  levator  ani  is  the 

Coccygeus. — Or.  narrow  from  the  inner  surface  of 
the  spine  of  the  ischium.  Ins.  into  the  side  of  the 
coccyx. 

The  arteries  met  with  in  the  perinseum  are  the 
transversus  perinsei,  perinaeal,  and  the  art.  of  the 
bulb,  branches  of  the  int.  pudic.  Around  the  anus 
are  the  inferior  hemorrhoidal  arteries.  The  nerves 
proceed  from  the  int.  pubic  and  sciatic. 

SECTION  VIII. 

The  Female  Organs  of  Generation 

are  divided  into  the  external  and  internal.  The  ex- 
ternal are  the  mons  veneris,  vulva,  labia,  clitoris,  nym- 
phce,,  and  vagina. 

The  mons  veneris  is  the  eminence  on  the  anterior 
surface  of  the  pubes.  The  vulva  is  the  slit-like 
aperture  between  the  labia.  The  labia  externa,  or 
majora,  are  the  folds  of  integument  on  each  side  of 
the  vulva ;  they  commence  at  the  mons  veneris,  and 
terminate  posteriorly  in  the  commissure  or  fourchette, 
behind  which  is  the  fossa  navicularis;  their  struc- 
ture is  composed  of  skin  externally,  mucous  mem- 
brane internally,  enclosing  some  cellular  vascular 
tissue.  The  nymphce,  or  labia  minor  a  descend  out- 
wards from  the  prepuce  of  the  clitoris,  and  are  lost 
about  the  centre  of  the  vulva  on  the  labia  majora ;  the 
orifice  of  the  urethra  lies  between  them.  The  clitoris 
is  analogous  to  the  male  penis ;  it  is  covered  ante- 
riorly by  an  irregular  prepuce,  continuous  interiorly 
with  the  nymphss.  It  contains  no  canal.  M.  Huguier 
has  recently  described  two  glands,  situated  one  on 
each  side  and  within  the  vagina,  which  opens  by 
ducts  near  the  margin  of  the  hymen. 


112  FALLOPIAN   TUBES. 

The  vagina  is  the  canal  leading  from  the  vulva 
upwards  and  backwards  to  the  uterus  ;  it  is  slightly 
curved,  the  concavity  towards  the  pubes,  and  passes 
between  the  urethra  and  bladder  above,  and  the  rec- 
tum behind ;  at  its  internal  extremity  it  surrounds 
the  neck  of  the  uterus,  passing  farther  on  its  poste- 
rior than  anterior  surface.  The  structure  of  the 
vagina  is  composed  exteriorly  of  an  erectile  vascular 
tissue  lined  by  mucous  membrane :  this  is  irregular, 
and  presents  near  the  orifice  the  hymen,  a  crescentic 
fold,  the  remains  of  which  form  the  cunmculw  myrti- 
formes;  this  membrane  possesses  a  number  of  mucous 
glands  and  follicles. 

The  internal  organs  of  generation  in  the  female  are 
the  Uterus,  Ovaries,  and  Fallopian  tubes. 

The  Uterus  is  situated  in  the  pelvis,  between  the 
bladder  and  rectum ;  pyriform  in  shape,  its  superior 
fundus  larger,  is  turned  upwards  and  forwards,  its 
inferior  fundus  directed  a  little  backwards  is  round- 
ed, and  terminates  by  a  slight  expansion,  behind 
which  is  the  cervix  uteri ;  the  anterior  and  posterior 
surfaces  somewhat  flattened,  are  partially  covered 
by  peritoneum;  its  edges  rounded  afford  attachment 
to  the  broad  ligaments,  and  at  the  superior  extremity 
to  the  Fallopian  tubes  and  ligaments  of  the  ovary. 

The  structure  of  the  uterus  is  composed  of  an  ex- 
ternal serous  partial  covering  from  the  peritoneum, 
beneath  which  is  a  peculiar  firm  tissue,  about  half 
an  inch  in  depth,  dense  as  cartilage,  and  composed 
chiefly  of  muscular  fibres ;  its  interior  is  lined  by 
mucous  membrane.  The  cavity  of  the  uterus  com- 
mences at  the  os  or  mouth;  this  is  a  transverse  aper- 
ture, hence  os  tincce,  which  leads  into  the  general 
cavity ;  this  widens  a  little  in  the  centre,  and  branches 
off  on  either  side,  and  superiorly  into  a  small  canal 
which  leads  into  the  Fallopian  tubes. 

The  Fallopian  tubes,  one  on  each  side,  proceed  from 
the  superior  and  lateral  portion  of  the  uterus  out- 


LIGAMENTUM   TERES.  113 

wards  to  the  extent  of  about  four  inches,  contained  in 
the  broad  ligament,  and  terminate  in  an  irregular 
expansion,  the  corpus  fimbriatum ;  the  cavity  of  the 
Fallopian  tube  is  small,  and  terminates  on  the  corpus 
fimbriatum  by  a  small  aperture,  morsus  diaboli. 

The  Ovaries,  or  female  testes,  are  attached  also  to 
the  superior  end  of  the  uterus  immediately  behind 
the  Fallopian  tubes.  They  are  contained  in  the  broad 
ligament,  and  are  attached  to  the  uterus  by  an  imper- 
vious ligament.  The  ovaries  are  covered  by  perito- 
neum, beneath  which  is  a  fibrous  coat;  the  interior 
is  composed  of  a  number  of  vesicles ;  Graafian  vesi- 
cles, from  six  to  ten  or  twelve  on  each  side. 

The  Uterus  is  supplied  with  blood  by  the  uterine 
arts,  from  the  int.  iliac ;  its  veins  terminate  in  the 
int.  iliac  veins;  its  nerves  are  derived  from  the  sym- 
pathetic. The  ovaries  receive  their  supply  of  blood 
from  the  spermatic  arteries. 

The  Ligamentum  teres  is  an  analogue  to  the  sper- 
matic cord  in  the  male,  although  it  does  not  perform 
any  special  function.  It  is  composed  of  cellular  tis- 
sue, nerves,  &c.,  and  stretches  from  the  upper  ext. 
of  the  uterus,  in  front  of  the  Fallopian  tubes,  to  the 
labium  pudendi. 

The  Perinseum  in  the  female  is  comparatively  un- 
important; it  extends  from  the  fourchette  back- 
wards to  the  anus,  and  has  muscles  analogous  to 
those  in  the  male. 


10* 


114 
CHAPTER  V. 

THE    INFERIOR   OR   LOWER   EXTREMITIES. 

are  connected  to  the  trunk  by  numerous  muscles  and 
ligaments;  the  former  extend  from  the  pelvis  and 
spine,  the  latter  from  the  ligaments  of  the  hip-joint. 

Beneath  the  integuments  covering  the  lower  extre- 
mities is  found  a  quantity  of  superficial  fascia,  or 
loose  subcutaneous  cellular  tissue.  It  contains  nu- 
merous superficial  blood  vessels,  nerves  and  lympha- 
tic glands,  of  these  the  largest  is  the  int.  saphena 
vein,  which  may  be  traced  from  the  foot  upwards 
to  its  termination  in  the  femoral  vein.  The  arteries 
are  chiefly  branches  from  the  femoral,  the  nerves 
from  the  anterior  crural  and  lumbar  plexus. 

Beneath  this  is  a  dense  layer  of  fascia,  the  fas- 
cia lata,  the  strongest  in  the  body,  which  not  only 
invests  the  muscles,  but  sends  septa  in  between 
them.  (See  Fasciae.) 

Muscles  of  the  Lower  Extremity. 
Of  the  Hip-Joint,  7. 

Gluteus  Maximus,  Or.  1,  post,  fifth  of  the  crista  ilii, 
and  rough  surface  beneath  it,  down  to  the  super,  semi- 
circular ridge;  2,  from  the  lumbar  fascia  and sacro- 
iliac  ligaments;  3,  from  the  sides  of  the  sacrum  and 
coccyx  and  post,  sacro-iliac  ligament;  4,  from  the 
fascia  of  the  gluteus  medius.  Ins.  by  a  flat  thick 
tendon  into  an  irregular  longitudinal  surface,  leading 
from  the  great  trochanter  to  the  linea  aspera  of  the 
femur,  and  into  the  fascia  lata  just  below.  .  Use,  to 
extend,  abduct,  and  rotate  the  thigh  outwards ;  to 
make  tense  the  fascia  lata,  and  to  fix  the  pelvis  on 
the  lower  extremity. 


ADDUCTORS.  115 

Glutens  medius,  Or.  1,  from  the  ant.  three-fourths 
of  the  christi  ilii,  and  ant.  sup.  spinous  process;  2, 
from  the  surface  of  the  ilium  between  its  two  curved 
lines.  Ins.  into  the  outer  part  of  the  great  trochan- 
ter.  Use,  to  abduct  the  thigh;  the  posterior  fibres 
rotate  the  limb  outwards,  the  anterior  inwards. 

Glutens  minimus,  Or.  from  the  inf.  curved  line  and 
surface  of  the  ilium  down  to  the  sup.  margin  of  the 
acetabulum ;  Ins.  ant.  half  of  the  margin  of  the  great 
trochanter.  Use,  similar  to  the  last. 

Pyriformis,  Or.  1,  by  three  slips  from  the  ant.  sur- 
faces of  the  second,  third,  and  fourth  divisions  of  the 
sacrum ;  2,  from  the  ant,  surface  of  the  great  sciatic 
ligament,  and  upper  edge  of  the  notch,  Ins.  post 
part  of  the  margin  of  the  great  trochanter.  Use,  to 
abduct  and  rotate  the  thigh  outwards. 

Obturator  internus,  Or.  1,  from  the  inner  surface 
of  the  obturator  fascia  and  fibrous  arch  of  the  obt. 
vessels  ;  2,  from  the  bony  margin  of  the  foramen  and 
surface  of  the  ischium,  between  it  and  the  sciatic 
notch ;  3,  from  the  upper  edge  of  the  true  pelvis.  Ins. 
into  the  digital  fossa.  Use,  to  abduct  and  rotate  the 
thigh  outwards. 

Gemelli,  (accessory  fibres  of  the  obt.  int.)  Or,  the 
upper  one,  from  the  spine  of  the  ischium ;  the  lower 
one,  from  its  tuberosity ;  they  enclose  the  obt.  ten- 
don, into  which,  and  into  the  digital  fossa,  they  are 
inserted ;  the  upper  one  is  sometimes  absent.  Use, 
to  abduct  and  rotate  the  thigh  outwards,  . 

Obturator  externus,  Or.  ant.  and  lower  part  of  the 
obturator  membrane,  and  corresponding  portions  of 
the  margin  of  the  foramen ;  its  tendon  passes  in  a 
groove  between  the  tuber  ischii  and  the  edge  of  the 
acetabulum,  winds  around  the  neck  of  the  femur,  to 
be  Ins.  into  the  digital  fossa  below  the  other  mus- 
cles. Use,  to  abduct  and  rotate  the  thigh  outwards. 

The  abductor  and  external  rotator  muscles  of  the  thigh 
are  7  in  number,  and  arise  successively  in  a  line 


116  ADDUCTOR  LONGUS. 

%, 

which  may  be  traced  along  the  sides  of  the  lumbar 
vert,  crista  ilii,  pectineal  line,  body  and  ramus  of 
the  pubis,  and  remus  and  tuberosity  of  the  ischium. 

Psoas  minor,  Or.  sides  of  the  bodies  of  the  last  dor- 
sal and  the  first  (and  sometimes  the  second)  lumbar 
vertebrae :  its  narrow  tendon  expands  to  be  Ins.  into 
the  ilio-pectineal  line,  and,  by  its  outer  edge,  into 
the  fascia  iliaca :  it  tenses  that  fascia,  and,  by  thus 
confining  the  two  following  muscles  in  their  places, 
may  be  deemed  their  accessory.  It  also  acts  upon 
the  vert,  column  and  pelvis. 

Psoas  magnus,  Or.  by  slips,  the  intervals  between 
which  give  passage  to  the  spinal  nerves,  from  the 
sides  of  the  bodies  and  intervert.  substances  of  the 
last  dorsal  and  the  five  lumbar  vert.,  and  from  the 
roots  of  the  corresponding  transverse  processes ;  Ins 
by  a  tendon  equally  shared  by  the  iliacus,  into  the 
smaller  trochanter.  The  lumbar  plexus  of  nerves  is 
imbedded  in  its  substance.  Use,  to  flex  the  thigh  and 
rotate  it  outwards,  to  bend  the  body  forwards. 

Iliacus,  Or.  1,  from  the  margin  and  the  entire  sur- 
face of  the  iliac  fossa ;  2,  from  the  two  ant.  spinous 
processes :  3,  from  the  base  of  the  sacrum ;  4,  from 
the  capsule  of  the  hip-joint.  Ins.  with  the  tendon 
of  the  psoas  mag.  into  the  smaller  trochanter.  Use, 
to  flex  and  rotate  the  thigh  upwards.  These  two 
muscles  pass  in  front  of  the  capsular  lig.  of  the  hip- 
joint,  from  which  they  are  separated  by  a  large 
buBsa  mucosa. 

Pectineus,  Or.  1,  from  the  spine  of  the  pubis  and 
the  pectineal  line  ;  2,  from  the  inf.  surface  of  an  apo- 
neurosis  continued  from  Gimbernaut's  ligament. 
Ins.  into  the  commencement  of  a  line  leading  from 
the  trochanter  minor  to  the  linea  aspera ;  separated 
from  the  psoas  by  the  femoral  artery,  as  it  lies  in 
front  of  the  quadratus  femoris.  Use,  to  adduct,  flex, 
and  rotate  the  thigh  outwards. 

Adductor  longus.  Apparently  continuous  at  its 
origin  with  the  pectineus,  Or.  by  a  flat  tendon  from 


SARTORIUS.  117 

the  spine  of  the  pubis;  Ins.  into  the  middle  third  of 
the  linea  aspera,  in  front  of  the  abductor  magnus. 

Abductor  Brevis,  Or.  body  of  the  pubis  below  the 
spine  and  between  the  gracilis  and  obturator  exter- 
nus;  Ins.  in  front  of  the  abductor  magnus,  into  the 
line  leading  from  the  trochanter  minor  to  the  linea 
aspera,  below  the  Ins.  of  the  pectineus.  The  three 
last  muscles  lie  on  a  plane  anterior  to  that  occupied 
by  the  two  following, 

Adductor  magnus,  Or.  1,  ramus  of  the  pupis  and 
ischium;  2,  lower  part  of  the  tuberosity  of  the  ischium. 
Ins.  fleshy  into  the  whole  length  of  the  middle  ridge 
of  the  linea  aspera,  and  into  a  line  leading  from  it  to 
the  great  trochanter  above,  and  to  the  inner  condyle 
below  ;  2,  by  a  tendon  into  a  tubercle  on  the  post,  and 
upper  part  of  the  inner  condyle.  An  opening  exists, 
between  the  two  portions,  at  the  lower  third  of  the 
thigh,  formed  especially  for  the  transmission  of  the 
femoral  vessels,  to  the  sheath  of  which  its  edges  are 
united.  Use,  the  three  adductors  adduct,  flex  and 
rotate  the  thigh  outwards. 

Quadratus  femoris,  quadrilateral,  Or.  from  the  outer 
edge  of  the  tuberosity  of  the  ischium,  and,  frequently, 
from  the  ramus  of  that  bone.  Ins.  into  the  line  leading 
from  the  trochanter  major  to  the  linea  aspera  :  it  ap- 
pears to  be  a  continuation  of  the  ad.  mag. ,  from  which 
it  is  only  separated  by  the  int.  circumflex  artery. 
Use,  to  adduct  and  rotate  the  thigh  outwards. 

Muscles  of  the  front  and  sides  of  the  thigh,  No.  7. 

Tensor  vaginse  femoris,  Or.  by  a  tendon,  from  the 
crista  and  ant.  sup.  spinous  process  of  the  ilium  be- 
tween the  sartorius  and  glutaeus  medius;  it  is  also  at- 
tached to  the  aponeurosis  of  the  latter  muscle;  it  de- 
scends slightly  backwards  to  the  Ins.  between  two 
lamellae  of  the  fascia  lata,  at  about  the  upper  third 
of  the  thigh.  Use,  to  make  tense  the  fascia,  and 
rotate  the  thigh  inwards. 


118  VASTUS   INTERNUS. 

Sartorius,  Or.  ant.  and  sup.  iliac  spinous  process, 
with  the  tensor  fascia,  and  from  half  of  the  interspi- 
nous  notch.  Its  tendon  expands  to  be  Ins.  into  the 
crista  of  the  tibia,  just  below  its  tuberosity;  its  ex- 
pansion covers  the  tendons  of  the  gracilis  and  semi- 
tendinosus;  it  also  strengthens  the  fascia  of  the  leg. 
Use,  to  flex  the  thigh,  adduct  and  rotate  it  inwards ; 
also  to  flex  the  leg  on  the  thigh  obliquely  so  as  to 
cross  over  the  opposite  limb. 

Gracilis,  Or.  by  a  thin  tendon,  from  the  inner  part 
of  the  pubis  symphysis,  from  the  spine,  to  the  ramus 
of  the  ischium,  internal  to  the  abductor  magnus.  Ins. 
into  the  crista  of  the  tibia,  above  the  semi-tendinosus. 
The  spreading  of  these  muscles  at  their  insertions  is 
termed  by  the  French  anatomists,  patte  d'  Oie.  Use, 
to  adduct  the  leg  and  thigh,  to  bend  the  knee,  and 
turn  the  leg  inwards. 

Quadriceps  extensor. 

Rectus  femoris,  Or.  1,  by  a  straight  tendon  from  the 
inf.  iliac  spinous  process ;  2,  by  a  reflected  tendon  from 
a  fossa,  just  above  the  edge  of  the  acetabulum.  Ins. 
by  a  strong  tendon  which  it  shares  with  the  vast!  and 
crureus,  into  the  ant.  surface,  and  edge  of  the  upper 
half  of  the  patella.  Use,  to  extend  the  leg  on  the 
thigh,  to  flex  this  on  the  pelvis. 

Vastus  externus,  Or.  1,  base  and  ant.  part  of  the 
great,  trochanter;  2,  from  the  tendinous  ins,  of  the 
gluteus  max.  and  short  head  of  the  biceps,  and  from 
the  outer  edge  of  the  whole  length  of  the  linea  aspera. 
Ins.  into  the  external  side  of  the  common  tendon  and 
the  patella:  it  covers  the  ext.,  part  of  the  crureus  at 
its  origin.  Use,  to  extend  the  knee,  and  rotate  the  , 
leg  outwards. 

Vastus  internus,  Or, I,  inter-trochanteric  line,  and 
whole  length  of  the  inner  edge  of  the  linea  aspera,  2, 
inner  surface  of  the  femur.  Ins.  into  the  inner  edge 
of  the  common  tendon,  and  the  patella,  and  by  an 
aponeurosis,  which  covers  the  inner  side  of  the  knee- 


SEMIMEMBRANOSUS.  119 

joint  into  the  head  of  the  tibia.     Use,  to  extend  the 
knee  and  rotate  the  leg  inwards. 

Cmreus,  inseparable  from  the  last  m.,  Or.  fleshy 
from  the  ant.  and  ext.  surface  of  the  upper  three- 
fourths  of  the  femur,  commencing  at  the  ant.  inter- 
trochanteric  line.  Ins.  upper  edge  of  the  patella 
with  the  common  tendon,  and  into  the  synovial  mem- 
brane behind  it.  A  large  bursa,  which  sometimes 
communicates  with  the  joint,  is  placed  between  its 
tendon  and  the  femur.  The  common  tendon  before 
it  reaches  the  patella,  is  separable  into  three  portions: 
the  anterior  one  belongs  to  the  rectus,  the  middle  to 
the  vastus  externus,  and  the  last  to  the  vastus  in- 
ternus  and  crureus.  The  ligamentum  patella  con- 
tinues them  from  the  anterior  surface  and  margin  of 
the  lower  half  of  the  patella,  to  the  tuberosity  of 
the  tibia.  Use,  to -extend  the  knee. 

Muscles  on  the  posterior  part^of  the  Thigh,  3  Flexors. 
Biceps,  flexor  cruris,  Or.  1,  by  its  long  head,  in  com- 
mon with  the  semitendinosus,  from  the  outer  and 
posterior  margins  of  the  tuber  ischii,  immediately 
below  the  inferior  gemellus,-  2,  by  its  short  head 
from  the  linea  aspera,  from  the  ins.  of  the  gluteus 
maximus,  to  within  two  inches  of  the  outer  condyle. 
Ins.  head  of  the  fibula.  Its  tendon  also  expands,  to 
strengthen  the  ext.  lat.  lig.  and  fascia  of  tfre  leg. 

Use,  to  flex  the  knee,  the  long  head  will  extend  the 
thigh  and  rotate  the  limb  outwards. 

Semitendinosus,  Or.  tuber  ischii,  with  the  long  head 
of  the  biceps.  Ins.  into  the  crest  of  the  tibia,  be- 
neath the  expanded  tendon  of  the  sartorius,  and 
below  the  tendon  of  the  gracilis,  to  which  it  is 
joined.  Use,  to  flex  the  knee  and  rotate  the  leg  in- 
wards; to  extend  the  thigh. 

Semimembranosus,  Or.  outer  part  of  the  tuber  ischii, 
in  front  of  the  biceps  and  semitendinosus.  Ins.  back 
part  of  the  inner  tuberosity  of  the  tibia:  from  this 


120  ARTERIES   AND    NERVES. 

point  a  process  is  sent  diagonally  across  the  joint,  to 
the  inner  part  of  the  ext.  condyle,  so  as  to  form  the 
greater  part  of  the  lig.  posticum;  another  winds,  in 
a  groove  lined  by  synovial  membrane,  horizontally 
round  the  inner  tuberosity  of  the  tibia,  into  which  it 
is  inserted;  and  a  third  expands  over  the  popliteus 
m.  Use,  to  extend  the  thigh,  to  flex  the  knee,  and 
rotate  the  leg  inwards. 

In  the  dissection  of  the  anterior  part  of  the  thigh, 
the  great  vessels  and  nerves,  viz.,  the  femoral  art., 
vein,  and  anterior  crural  nerve  are  found. 

The  Femoral  Art.  is  the  continuation  of  the  ext. 
iliac;  it  passes  beneath  Poupart's  ligament,  having 
the  vein  to  its  inner  side,  the  ant.  crural  nerve  to  its 
outer  side  and  at  some  distance  from  it ;  from  this 
the  femoral  art.  passes  downwards,  backwards,  and 
inwards,  and  finally  escapes  beneath  the  adductor 
magnus  tendon  into  the  popliteal  space,  and  assumes 
the  name  of  popliteal  art. ;  its  principal  branch  is 
the  profunda ;  the  femoral  vein  accompanies  the  art., 
at  first  lying  internal  to  it,  and  then  getting  pos- 
terior to  it.  The  anterior  crural  nerve  descends 
into  the  thigh  between  the  psoas  magnus  and  iliacus 
internus  muscles,  and  soon  divides  into  a  lash  of 
filaments  to  supply  the  principal  muscles  on  the  an- 
terior and  lateral  surfaces  of  the  thigh;  its  most  im- 
portant branch  is  the  int.  saphenous  nerve,  which 
accompanies  the  femoral  art.  in  its  lower  third,  and 
leaves  it  to  descend  with  the  anastomotica  magna  to 
the  knee,  below  which  it  joins  the  int.  saphena 
vein. 

The  arteries  met  with  on  the  back  part  of  the  hip 
and  thigh  are  the  gluteal,  sciatic  and  pudic  branches 
of  the  internal  iliac ;  the  first  two  descends  into  the 
thigh,  the  last  is  lost  about  the  perinaeum  and  or- 
gans of  generation. 

The  nerves  are  the  great  and  lesser  sciatic  nerves, 
branches  of  the  sacarl  plexus. 


MUSCLES    OF   LEG.  121 

SECTION   I. 
Of  the  Leg. 

Beneath  the  integuments  of  the  leg,  as  in  most 
other  parts  of  the  body,  is  found  the  superficial  fas- 
cia; in  it  are  contained,  on  the  inner  side  the  int. 
saphena  vein  and  saphenous  nerve;  on  the  posterior 
surface  the  ext.  saphena  vein  and  post,  saphenous 
nerve,  will  be  found,  but  beneath  the  fascia  of  the 
leg  at  its  upper  part. 

Beneath  the  superficial  fascia  is  a  strong  aponeu- 
rosis,  the  fascia  of  the  leg,  attached  on  either  side  to 
the  spines  of  the  tibia  and  fibula.  On  raising  this 
will  be  found  the 

Muscles  of  the  Leg,  13.     Those  in  Front,  3 

Tibialis  anticus,  Or.  1.  from  the  upper  two-thirds 
or  the  ext.  surface  and  crista  of  the  tibia,  as  far  as 
the  outer  tuberosity ;  2,  from  the  inner  half  of  the 
interosseous  ligament,  from  the  fascia  of  the  leg  and 
septa.  Ins.  into  a  tubercle  on  the  first  cuneiform 
bone,  and  base  of  the  first  metatarsal  bone.  Use,  to 
flex  the  ankle,  adduct  the  foot,  and  to  raise  its  inner 
edge  from  the  ground. 

Extensor  communis  digitorum,  Or,  1,  from  the  outer 
tuber  tibise,  with  the  tibialis  anticus;  2,  from  the 
whole  length  of  the  surface  of  the  fibula,  in  front  of 
the  interosseous  ligament,  and  slightly  from  that  lig., 
from  the  crural  fascia  and  septa.  Ins.  by  four  ten- 
dons, into  the  phalanges  of  the  four  lesser  toes,  like 
the  corresponding  m.  of  the  arm.  The  outer  fibres 
of  the  inf.  third  of  the  muscle  are  attached  to  a  fifth 
tendon.  Use,  to  extend  the  toes  and  flex  the  ankle. 

Extensor  proprius  pollicis,  Or.  middle  third  of  the 

ant.  surface  of  the  fibula  covered  by  the  last  m., 

slightly  from  the  interosseous  ligament,  from  the 

crural  fascia  and  septa ;  Ins.  by  two  fasciculi  into 

11 


122  GASTROCNEMIUS. 

the  first  and  second  phalanges.      Use,  to  extend  the 
great  toe  and  flex  the  ankle. 

Muscles  on  the  outer  part  of  the  Leg,  3. 

Peroneus  longus,  Or.  1,  outer  and  fore  part  of  the 
head  of  the  fibula,  and  ext.  surface  of  the  upper  two- 
thirds  of  that  bone ;  2,  slightly,  from  the  inner  tuber 
tibiae,  with  the  common  extensor  from  the  crural 
fascia  and  septa.  Ins.  into  a  tubercle  on  the  outer 
part  of  the  base  of  the  first  metatarsal  bone ;  its  ten- 
don crosses  the  foot  above  all  the  other  soft  parts, 
lodged  in  a  groove  in  the  cuboid  bone.  Use,  to  ex- 
tend the  ankle,  turn  the  foot  outwards,  and  raise  its 
outer  edge. 

Peroneus  brevis,  Or.  lower  half  of  the  outer  and 
posterior  surface  of  the  fibula ;  Ins.  base  of  the  fifth 
(sometimes  also  of  the  fourth)  metatarsal  bone.  Use, 
similar  to  the  last. 

Peroneus  tertius.  The  external  fibres  of  the  lower 
third  of  the  ext.  com.  m.  terminate  in  a  tendon  which 
is  ins.  into  the  upper  surface  of  the  fifth  metatarsal 
bone,  just  in  front  of  the  last  muscle.  Use,  to  flex 
the  ankle,  raise  its  outer  edge,  and  abduct  the  foot. 

Muscles  on  the  back  of  the  Leg,  1. 

Superficial  set,  4. 

Gastrocnemius,  Or.  by  two  heads,  each  of  which  is 
attached  to  a  depression  on  the  upper,  outer,  and  back 
part  of  each  condyle,  and  condyloid  ridges;  the  in- 
ner one,  the  larger,  just  behind  the  tendon  of  the 
abductor  mag.;  the  outer  one,  just  above  the  tendon 
of  the  popliteus.  The  resulting  two  fleshy  bellies 
are  united  in  a  raphe,  a  little  below  the  joint,  and 
terminate  at  the  middle  of  the  leg,  in  a  flat  tendon, 
which  almost  immediately  becomes  a  part  of  the  tend. 
Achillis.  Use,  to  extend  the  ankle-joint,  to  raise  the 
body  in  walking,  to  flex  the  knee-joint. 


FLEXOR   COMMUNIS.  123 

Plantaris,  Or.  ext.  condyloid  line,  and  fibrous  cap- 
sule over  the  outer  condyle ;  its  long  narrow  tendon 
runs  to  the  inner  edge  of  the  tendo  Aehillis,  to  be 
Ins.  into  the  calcaneum,  or  merely  into  the  fatty  tis- 
sue, before  the  insertion  of  that  tendon.  Sometimes 
double.  Use,  to  aid  the  preceding. 

Soleus,  Or.  1,  tendinous,  from  the  inner  and  back 
part  of  the  head  of  the  tibia,  and  aponeurotic,  from 
the  post,  surface  and  outer  edge  of  the  upper  third, 
of  the  fibula  ;  2,  from  the  popliteus  fascia  post,  obli- 
que line  of  the  tibia,  and  from  a  third  of  its  inner 
edge:  just  below,  its  tendon,  with  that  of  the  gas- 
trocnemius,  forms  the  tendo  Aehillis, which  is  Ins. 
into  the  lower,  and  back  part  of  the  calcaneum. 
Use,  to  extend  the  ankle  and  assist  the  progression 
by  raising  th'e  os  calcis  from  the  ground. 

Popliteus,  Or.  narrow,  from  a  fossa  on  the  back 
part  of  the  outer  condyle  of  the  femur ;  Ins.  broad, 
into  all  the  triangular  surface  of  the  tibia,  above  its 
oblique  line:  the  tendon  is  covered  by  the  ext.  lat. 
ligament,  and  surrounded  by  the  synovial  membrane 
of  the  joint.  Use,  to  flex  the  knee,  and  when  flexed 
to  turn  the  leg  inwards. 

Deep  set,  3. 

Tibialis  posticus,  lies  in  the  posterior  interosseous 
space ;  Or.  by  two  fleshy  slips,  between  whicli  passes 
the  ant.  tib.  art. ;  one  from  the  oblique  line  of  the 
tibia,  below  the  popliteus,  soleus,  and  common  flexor; 
the  other  from  the  inner  edge  of  the  fibula,  below  the 
soleus;  also,  the  whole  of  the  interosseous  ligament, 
and  adjoining  surface  of  the  fibula.  Ins.  with  a  se- 
samoid  bone  into  a  tubercle  on  the  inner  side  of  the 
scaphoid  bone.  Use,  to  extend  the  ankle,  and  raise 
the  inner  edge  of  the  foot  from  the  ground. 

Flexor  digitorum  communis  perforans,  Or.  posterior 
surface  of  the  tibia,  between  the  oblique  line  and  a 
point  two  inches  above  the  inner  malleolus  ;  Ins.  into 


124  SOLE   OF   FOOT. 

the  last  phalanges  of  the  four  smaller  toes,  like  the 
corresponding  muscles  of  the  fingers.  Use,  to  flex  the 
toes,  to  extend  the  ankle,  and  assist  in  raising  the 
body  from  the  ground  in  progression. 

Flexor  pollicis  pedis,  the  largest  muscle  of  this  set, 
Or.  inf.  two-thirds  of  the  post,  surface  of  the  fibula: 
Ins.  into  the  last  phalanx  of  the  great  toe,  like  the 
corresponding  muscle  of  the  thumb.  Use,  to  flex  the 
great  toe  and  extend  the  ankle. 

Muscles  of  the  Foot. 
Of  the  Dor  sum,  1. 

Dorsalis  pedis,  Or.  from  the  outer  and  upper  part 
of  the  calcaneum,  and  adjoining  portion  of  the  ext. 
calcaneo-cuboid  ligament ;  Ins.  by  four  tendons,  of 
which  the  three  last  are  ins.  into  the  expansion  of  the 
common  extensor  tendons  on  the  first  phalanges  of 
the  second,  third,  and  fourth  toes,  and  the  first  into 
the  base  of  the  first  phalanx  of  the  great  toe.  Use,  to 
extend  the  four  inner  toes. 

The  Sole  of  the  Foot. 

The  integuments  covering  the  sole  of  the  foot  arc 
remarkablydense, particularly  where  exposed  to  pres- 
sure, as  on  the  heel  and  outer  side  of  the  foot ;  beneath 
these  is  a  thick  layer  of  adipose  substance,  collected 
into  small  masses  so  as  to  form  an  elastic  cushion  to 
preserve  the  subjacent  parts  from  injury  in  progres- 
sion; beneath  this  is  a  dense  layer  of  fibrous  tissue,  the 
plantar  aponeurosis  ;  triangular  in  shape  it  is  attached 
posteriorly  by  its  apex  to  the  tubercles  on  the  os  calcis, 
passes  forwards,  spreads  out,  and  divides  into  three 
portions;  of  these  the  central  is  the  strongest,  the 
outer  the  next  in  strength,  and  the  inner  the  weak- 
est ;  these  send  in  processes  between  the  muscles;  the 
lateral  are  attached  to  the  sides  of  the  tarsus  and  me- 
tatarsus, the  central  portion  divides  anteriorlyinto  five 


MUSCLES    OP   FOOT.  125 

fasciculi,  which  again  subdivide,  and  are  attached  to 
the  lateral  ligaments  of  the  metatarso-phalangeal  ar- 
ticulations, leaving  intervals  for  the  passage  of  the 
digital  tendons,  vessels,  and  nerves.  Beneath  this 
are  the 

Planter  Muscles*  19. 
Of  the   Inner   Edge,  4. 

Abductor  pollicis,  Or.  1,  from  the  inner  tubercle  of 
thecalcaneum;  2,  from  the  int.  annular  lig.  and  plantar 
fascia.  Ins.  into  the  int.  sesam.  bone  of  the  base  of 
the  first  phalanx  of  the  great  toe,  with  the  inner  head 
of  the  flexor  brevis.  Use,  to  abduct  the  great  toe. 

Flexor  brevis  pollicis,  Or.  from  the  two  last  cunei- 
form bones,  and  from  the  ant.  part  of  the  calcaneum 
and  their  ligaments ;  Ins.  by  two  heads  with  the  ab- 
ductor and  adductor  pollicis,  into  the  sesamoid  bones 
and  base  of  the  first  phalanx.  Use,  to  flex  the  first 
joint  of  the  great  toe. 

Adductor  pollicis  is  placed  in  the  hollow  formed  by 
the  lower  surfaces  of  the  four  last  metatarsal  bones ; 
Or.  cuboid  and  bases  of  the  three  last  metatarsal  bones, 
and  from  the  sheath  of  the  peroneus  long,  tendon ; 
Ins.  with  the  outer  head  of  the  last  m.  into  the  ext. 
sesamoid  bone.  Use,  to  abduct  and  flex  the  great  toe. 

Adductor  secundus  vel  transversus  pedis,  Or.  from 
the  head  of  the  last  metatarsal  bone,  and  phalangeal 
ligaments  of  the  two  next ;  Ins.  outer  edge  of  the  first 
phalanx  of  the  great  toe,  close  to  the  last  muscle. 

Muscles  of  the  outer  Edge  of  the  Foot,  2-3. 

Abductor  minimi  digiti,-Or.  from  the  ext.  tubercle 
of  the'calcaneum,  and  sometimes  from  the  base  of  the 
last  metatarsal  bone ;  Ins.  outer  side  of  the  base  of 
the  first  phalanx  of  the  little  toe.  Use,  to  abduct 
and  flex  the  little  toe. 

Flexor  digiti  minimi  resembles  an  interosseous  m. 
Or.  base  of  the  fifth  metatarsal  bone  and  adjoining  li- 


126  RELATION    OP   PARTS. 

gaments;  Ins.  on  the  outer  part  of  the  base  of  the 
first  phalanx.  A  few  fasciculi  from  the  same  origins 
may  sometimes  be  traced  to  the  whole  of  the  outer 
edge  of  the  fifth  metatarsal  bone.  These  might  be 
called  opponens  digiti  minimi.  Use,  to  flex  and  adduct 
the  little  toe. 

Muscles  in  the  Middle  of  the  Foot,  13. 

Flexor  brevis perforatus,  Or.  1,  from  the  calcaneum, 
between  the  tubercles ;  2,  from  the  plantar  fascia, 
and  septum  on  each  side.  Ins.  by  slips,  into  the  four 
smaller  toes,  like  the  flexor  perforatus  of  the  hand. 
Use,  to  flex  the  four  outer  toes. 

Flexor  accessorius,  Or.  inferior  surface  of  the  cal- 
can.,  and  calcan.  scaphoid  ligament ;  Ins.  1,  into  the 
outer  edge  of  the  tendon  of  the  common  flexor;  2, 
strengthened  by  a  process  from  the  tendon  of  flex, 
long,  pol.,  into  the  upper  surfaces  of  each  tendon  of 
the  common  flexor.  Use,  to  flex  the  toes  with  or 
without  the  long  flexor. 

Lumbricales  resemble  precisely  the  corresponding 
fasciculi  in  the  hand.  Use,  to  adduct  and  flex  the 
four  outer  toes. 

The  Interossei  are  seven  in  number,  as  in  the  hand ; 
viz.,  four  dorsal  and  three  plantar,  the  former  being 
abductors,  the  latter  adductors;  but,  in  the  foot,  the 
median  line,  or  axis  of  the  second  toe,  must  be  taken 
as  the  fixed  point.  The  first  dorsal  interosseous 
muscle  is  attached  to  the  tibial  side  of  the  second 
toe;  the  second  to  the  fibular  side  of  the  same  toe; 
the  third,  to  the  fibular  side  of  the  third  toe ;  the 
fourth,  to  the  fibular  side  of  the  fourth  toe.  The  plan- 
tar are  attached,  the  first,  to  the  tibial  side  of  the  third 
toe;  the  second,  to  the  tibial  of  the  fourth  toe;  the 
third,  to  the  tibial  side  of  the  fifth  or  little  toe. 

The  relations  of  the  parts  about  the  ankle  joint,  are 
as  follows:  A.  Posteriorly,  1,  the  inner  malleolus,  and 
the  groove  and  sheath  containing  the  tendons  of  the 
tibialis  posticus  and  common  flexor ;  2,  the  tendon  of 
the  flexor  pollicis,  which  lies  close  to  the  calcaneum, 


ARTERIES  OF  LEG  AND  FOOT.     127 

separated  by  a  space  of  an  inch  and  a  quarter  from 
the  last-named  tendons;  3,  the  post,  tibial  vessels  and 
nerve  in  the  middle  of  this  space,  or  somewhat  nearer 
the  flex.  pol.  tendon,  and  superficially,  the  intern, 
saphen.  nerve  and  vein;  4,  the  tendon  of  theplantaris, 
tendo  Achillis,  and  tuberosity  of  the  calcaneum ;  5, 
the  communicans  tibiae,  nerve,  ext.  saphena  vein,  and 
more  deeply,  the  termination  of  the  peroneal  artery; 
6,  the  ext.  malleolus,  and  immediately  behind  it,  the 
tendons  of  peronei  long  et  brevis,  in  a  single  groove 
and  sheath.  B.  Anteriorly,  1,  the  tendon  of  the  tibialis 
anticus;  2,  that  of  the  ext.  pollicis;  3,  surfaces  of  the 
tibia  and  astragalus  supporting  the  ant.  tibial  artery 
and  nerve ;  4,  tendons  of  the  common  extensor,  and 
tendon  of  the  peroneus  tertius. 

In  the  dissection  of  the  leg  and  foot,  the  principal 
vessels  and  nerves  met  with  are  the  anterior  and 
posterior  tibial  and  their  several  branches. 

The  femoral  art.  having  entered  the  popliteal  space 
assumes  the  name  of  popliteal ;  this  descends  nearly 
in  the  centre  of  the  space,  and  at  the  lower  margin  of 
the  popliteus  muscle  divides  into  its  two  terminating 
branches,  the  anterior  tibial,  the  smaller,  and  the  pos- 
terior tibial.  The  anterior  tibial  art.  passes  forwards 
through  the  interosseous  space  and  descends  on  the 
anterior  surface  of  the  interosseous  membrane,  passes 
beneath  the  anterior  annular  ligament  of  the' ankle- 
joint,  runs  forwards  and  inwards  to  the  cleft  between 
the  first  and  second  metatarsal  bones,  and  sinks  into 
the  sole  of  the  foot  to  anastomose  with  the  plantar  ar- 
teries; it  is  accompanied  in  the  lower  two-thirds  of  its 
course  by  the  ant.  tibial  nerve,  a  branch  from  the  pe- 
roneal or  fibular. 

The  posterior  tibial  art.  descends  obliquely  inwards 
along  the  posterior  surface  of  the  leg,  resting  on  the 
deep  muscles,  passes  behind  the  internal  malleolus, 
enters  the  sole  of  the  foot,  and  terminates  in  the  ext. 
and  int.  plantar  arteries,  of  these  the  external  is  the 


128    ARTERIES  OP  LEG  AND  FOOT. 

larger  and  supplies  three  and  a  half  toes  from  the 
little  toe  inwards,  the  int.  plantar  art.  supplies  the 
one  and  a  half  inner  toes. 

The  posterior  tib.  art.  is  accompanied  by  the  post, 
tib.  nerve,  which  terminates  like  it  in  the  side  of  the 
foot  in  two  plantar  nerves;  of  these  the  internal  is 
the  larger,  and  supplies  the  three  and  a  half  inner 
toes,  the  ext.  supplies  the  remaining  one  and  a  half 
toes. 

Shortly  after  its  origin,  the  post.  tib.  art.  gives 
off  its  largest  branch,  the  fibular;  this  descends  out- 
wards along  the  back  of  the  fibula,  and  terminates 
about  the  ankle-joint.  It  is  not  accompanied  by  any 


129 

CHAPTER  VI. 


Superficial  fascia.  An  areolar  tissue,  connected  by 
numerous  filaments  to  the  dermis ;  its  principal  use  is 
to  render  the  skin  movable  on  the  subjacent  parts, 
and  to  protect  the  subcutaneous  vessels  and  nerves ; 
it  may  also  be  considered  as  the  connecting  medium 
between  the  skin  and  aponeurosis.  The  subcutaneous 
cellular  tissue,  superficial  fascia,  and  the  proper  in- 
vestment of  muscles,  tendons,  &c.,  are  modifications 
of  the  same  tissue,  and  in  some  regions  it  is  difficult 
to  tell  where  the  one  begins  or  the  other  ends ;  in 
others  the  investing  fasciae  are  sufficiently  distinct, 
but  no  line  of  demarkation  distinguishes  the  subcuta- 
neous tissue  from  the  so-called  superficial  fascia,  the 
separation  is  always  more  or  less  arbitrary:  thus, 
in  the  inguinal  region,  where  it  forms  a  layer  of  some 
importance,  the  adipose  substance  and  cellules,  so 
frequently  developed  in  large  quantities  beneath  the 
skin,  must  always  be  cut  through,  in  raising  the 
latter  membrane,  in  order  to  demonstrate  a  superfi-. 
cial  fascia. 

Fascia,  aponeurosis.  These  terms  are  almost  indis- 
criminately employed  to  designate  those  layers  of  con- 
densed cellular  membranes,  which,  as  sheaths>  septa, 
or  linings,  preserve  the  various  organs  of  the  body  in 
their  forms  and  relations.  The  fascia  transversalis  is 
an  example  of  the  latter,  and  the  fascia  lata  is  the 
best  specimen  of  a  sheath.  This  fascia  surrounds  the 
whole  inferior  extremity,  and  sends  numerous  pro- 
cesses or  septa  from  its  inferior  surface,  some  of  which 
form  secondary  sheaths  for  the  muscles,  vessels,  and 
nerves  of  the  limb.  If  all  these  organs  could  be  re- 
moved without  injury  to  an  aponeurotic  investment  of 
this  kind,  a  faithful  outline  of  their  form  and  relative 
position  would  still  remain;  in  fact,  the  whole  body, 


130  ABDOMINAL   FASCIAE. 

if  it  could  be  subjected  to  such  a  process,  would  re- 
present a  skeleton  of  cavities  and  tubes,  admirably 
adapted  for  the  protection  and  support  of  their  re- 
spective organs. 

Fascia  cervicalis  (superficialis.)  The  superficial 
fascia  of  this  region  contains  a  cutaneous  muscle,  the 
platysma  myoides;  it  may  be  traced  from  the  median 
line  completely  round  the  neck ;  above,  it  is  lost 
with  the  platysma  on  the  face ;  and  below,  on  the 
muscles  of  the  chest;  on  the  sterno-mastoid  muscle 
it  is  identified  with  the  next  fascia ;  both  are  inti- 
mately united  elsewhere,  but  can  be  separated  with- 
out much  difficulty. 

Fascia  cerv.  profunda.  A  dense  aponeurotic  line 
extends  from  the  symphysis  of  the  chin  to  the  os 
hyoides,  and  onwards  to  the  inner  part  of  the  first 
bone  of  the  sternum:  from  each  side  of  this  line  the 
fascia  may  be  traced  round  the  neck  to  its  posterior 
part.  It  furnishes  a  sheath  for  the  sterno-mastoid 
muscle,  and  another  for  the  submaxiliary  gland,  which 
is  thus  separated  from  the  parotid ;  its  processes  form 
a  sheath  for  the  carotid  artery,  jugular  vein,  and  va- 
gus nerve,  another  for  the  omo-hyoid  muscle,  by  which 
it  is  enabled  to  preserve  its  angular  directions,  and 
several  less  remarkable  for  the  remaining  organs,  lym- 
phatics, &c.,  in  this  region.  A  layer  separates  the 
sternal  muscles  from  the  trachea,  and  descends  to  be 
connected  with  a  dense  tissue,  which  so  strongly  ties 
the  great  vessels  to  the  inside  of  the  sternum ;  accord- 
ing to  Todd  and  Bowman,  it  even  reaches  the  pericar- 
dium: above,  the  deep  cervical  fascia  is  attached  to 
the  base  of  the  jaw,  and  the  stylo-maxiliary  ligament, 
and  over  the  parotid  to  the  zygoma;  below,  to  the  in- 
ner side  of  the  clavicle  and  first  bone  of  the  sternum. 

Abdominal  Fascise  and  Aponeurosis. 

The  superficial  fascia  deserves  most  attention  in  the 
inguinal  and  crural  regions ;  there  it  presents  a  well- 


LIGAMENTUM   ARCUATUM.  131 

developed  layer,  which  is  strongly  adherent  a  little 
below  Poupart's  ligament;  it  descends  on  the  thigh, 
and,  on  the  cord  and  testicle,  to  form  one  of  the  scro- 
tal  coverings.  In  early  life  it  is  said  to  occupy  the 
inguinal  canal,  as  a  gubernaculum  for  the  descent  of 
the  testis.  Its  crural  portion  is  loaded  with  lympha- 
tic glands  and  small  vessels. 

Sheath  of  the  Rectus.  The  int.  obliquus  muscle  ter- 
minates in  an  aponeurosis,  which  at  the  linea  semilu- 
naris  is  intimately  united  to  that  of  the  transversalis 
m.,  and  then  splits  into  two  layers;  one,  closely 
united  to  the  aponeurosis  of  the  ext.  oblique,  passes 
to  the  linea  alba  in  front  of  the  rectus ;  the  other,  with 
the  aponeurosis  of  the  transversalis,  to  the  same  line 
behind  that  muscle :  but  where  the  rectus  covers  the 
ribs,  and  from  a  point  midway  between  the  umbili- 
cus and  pubes  to  the  pubes,  the  sheath  wants  its 
post,  paries,  inasmuch  as  the  four  conjoined  aponeu- 
roses  there  pass  in  front  of  the  m,uscle. 

Sheath  of  the  quadratus  lumb.,  lumbar  fascise.  At 
the  outer  edge  of  the  quadratus  m.,  the  inter,  oblique 
and  transversalis  also  terminate  in  one  aponeurosis, 
which  immediately  afterwards  splits  into  three  layers. 
The  posterior  owe  passes  behind  the  common  origin 
of  the  longissimus  dorsi  m.  to  the  tips  of  the  lumbar 
spinous  processes:  it  is  confounded  with  the  apon. 
of  the  ser.  post.  inf.  and  latissimus  dorsi  muscles. 
The  middle  one  passes  between  the  long,  dorsi  in.  and 
the  quadratus  lumbar.,  and  is  inserted  into  the  tips 
of  the  lumbar  transverse  processes.  The  internal, 
thin  and  weak,  better  understood  as  a  continuation  of 
the  fascia  transversalis,  which  it  so  much  resembles, 
passes  in  front  of  the  quadratus  to  the  transverse 
processes,  and  then  over  the  psoae  to  the  bodies  of 
the  lumb.  vertebrae. 

Ligamentum  arcuatum  (Pseud.)  The  upper  part  of 
the  fascia  transv.  post,  arching  over  the  quadratus 
muscle,  from  the  tip  of  the  last  rib  to  the  transverse 
process  of  the  first  lumbar  vertebra. 


132  PERIN^EL   FASCIA 

Lig.  arcuat  (verum,)  the  upper  part  of  the  same 
fascia  arching  over  the  psose,  from  the  transverse 
process  of  the  first  lumbar  vertebra  to  the  body  of 
the  second.  Both  these  ligaments  afford  attachments 
to  the  diaphragm,  on  the  under  surface  of  which  the 
fascia  trans,  post,  is  continued. 

Fascia  transversalis  (anterior.)  Hardly  perceptible 
at  the  umbilicus,  it  increases  in  density  as  it  descends, 
and  at  the  inguinal  region  appears  as  a  dense  shining 
membrane  intimately  adherent  to  the  fibres  of  the 
muscle  (it  is  a  muscular  fascia.)  Behind  the  pubis, 
and,  at  Poupart's  ligament,  external  to  the  femoral 
vessels,  it  joins  the  pelvic  fascia;  where  it  meets  the 
vessels,  it  joins  the  superficial  division  of  the  fascia 
lata  (fascia  cribrif.)  to  form  the  ant.  paries  of  the 
crural  canal.  The  spermatic  cord  derives  an  invest- 
ment (fascia  prop.)  from  it,  in  its  passage  through 
the  inguinal  canal. 

Pelvic  fascia.  A  fine  dense  muscular  fascia,  resem- 
bling the  fascia  transversalis,  to  which  it  is  connected 
along  the  base  of  the  sacrum,  crista  ilii,  Poupart's 
ligament  external  to  the  vessels,  and  at  the  pubis.  It 
covers  the  iliacus  muscle,  as  the  iliacus  fascia,  and 
passes  over  the  psose,  beneath  the  iliac  vessels,  sending 
a  thin  layer  in  front  of  these,  to  descend  some  way  on 
the  obturator  m.  as  the  internal  obturator  fascia,  but, 
at  a  line  extending  from  the  pubis  to  the  spine  of  the 
ischium,  it  is  reflected  upon  the  upper  surface  of  the 
levator  ani  m.,  which  guides  it  to  the  sides  of  the 
bladder  forming  the  true  lateral  ligaments  of  this  vis- 
cus,  vagina,  and  rectum :  behind,  it  is  reflected  from 
the  sacrum  and  coccygeus  m.  to  the  rectum ;  and  be- 
fore, from  the  body  of  the  pubis  and  Wilson's  mus- 
cles, as  the  true  vesicle  ligaments,  to  the  neck  of  the 
bladder  and  prostate  gland.  This  portion  might  be 
called  the  inner,  or  deep  perineal  fascia. 

Perineal  fascist,  1 ,  the  superficial,  is  analogous  to  the 
superficial  fascia  in  other  parts.  2,  the  perineal. 


FASCIA   LATA.  133 

The  fascia  is  continuous  in  front  with  that  of  the 
scrotum :  on  each  side  it  is  firmly  adherent  to  the 
ramrof  the  ischium  and  pubis ;  behind,  at  a  line  ex- 
tending from  one  tuber  ischii  to  the  other,  it  is  also 
adherent  to  the  middle  perineal  fascia ;  here  it  is 
said  to  terminate  (Blandin,)  but  it  may  still  Joe 
traced,  covering  the  levator  ani,  and  filling  up  with 
a  mass  of  fat,  the  triangular  space  on  the  inside  of 
the  tuber  ischii,  formed  by  that  muscle  and  the 
lower  part  of  the  obturator  internus.  The  sup  er- 
ficial  sphincter  ani  is  developed  in  it. 

The  posteriorly  deep  fascia  of  the  perineum,  impro- 
perly called  triangular  ligament  of  the  urethra,  arises 
from  the  sub-pubic  ligament,  rami  of  the  ischium 
and  pubis,  tuber  ischii,  inner  edge  of  the  great  sacro- 
sciatic  ligament,  and  coccyx:  from  these  attach- 
ments it  passes  inwards  to  the  median  line,  That 
part  which  is  before  the  transverse  line  is  composed 
of  strong  transverse  fibres ;  to  this  the  term  triangu- 
lar ligament  is  applied.  Behind  this  line,  it  first 
ascends  on  the  inner  side  of  the  obturator  internus 
as  far  as  the  line  of  reflection  of  the  obturator  por- 
tion of  the  pelvic  fascia,  and  then  turns  down  on 
the  lower  surface  of  the  levator  ani  m.  The  triangu- 
lar space  lies  between  these  two  portions  of  fascia. 
The  middle  part  of  the  levator  ani  arises  from  the 
line,  where  the  obturator  fascia  from  the  pelvic,  and 
that  from  the  middle  perineal  fascia,  are  united.  The 
ejaculatores  semin.,  erectores  penis,  and  transver- 
sales  m.,  superficial  perineal  nerves  and  vessels,  are 
enclosed  between  the  perineal  fascia  and  triangular 
ligament,  and  the  levator  ani,  coccygei,  and  Wilson's 
muscles,  between  the  latter  and  pelvic  fascia.  The 
middle  perineal  fascia  bifurcates  at  the  rami  ischii 
et  pubis,  to  enclose  the  internal  pubic  artery.  Fluid 
effused  in  the  anterior  perineal  sheath  before  the 
transverse  line,  will  infiltrate  the  cellular  tissue  of 
the  scrotum. 
12 


134  FASCIA   LATA. 

Fascia  lata.  A  dense,  fibrous  sheath,  enclosing  the 
lower  extremity.  Numerous  septa  and  sheaths  are 
sent  from  this  fascia  to  the  vessels  and  muscles  of  the 
limb.  The  most  remarkable  are — 1.  The  Ext.  inter- 
muscular  septum,  which  extends  from  the  trochanter 
major  to  the  ext.  condyle;  its  inner  edge  is  attached 
to  the  whole  length  of  the  linea  aspera,  and  separates 
the  vastus  ext.  from  the  short  head  of  the  biceps,  to 
both  of  which  it  gives  attachment.  2.  The  Int.  inter- 
muscular  septum  extends  from  the  inter-trochanteric 
line  to  the  internal  condyle.  It  separates  the  adduc- 
tors from  the  vastus  int.  The  femoral  vessels  and 
saphenous  nerve  are  enclosed  in  a  sheath  derived  from 
the  fascia  lata,  the  upper  part  of  which  is  the  crural 
canal.  The  lower  part  of  the  sheath  is  formed  by  a 
septum,  which  is  sent  down  from  the  fascia  to  bifur- 
cate and  enclose  the  vessels ;  but,  above,  the  fascia 
(supposing  it  to  pass  inwards)  comes  in  contact  with 
the  vessels  enclosed  in  their  proper  sheath,  and  at  a 
falciform  line  (which  is  produced  by  the  tension  of  the 
fascia  between  Gimbernaut'sligamentjPoupart's  liga- 
ment, and  external  side  of  the  vessels, )  sends  off  a 
fascia  (cribriform)  in  front  of  the  vessels  and  then  re- 
flects itself  outwards  and  downwards  to  pass  und^r 
them,  in  order  to  join  the  fascia  cribiformis  at  their 
inner  side ;  thus  reunited,  the  fascia  passses  on  to  the 
inner  side  of  the  thigh.  It  now  appears  that  the 
crural  canal  is  formed  by  an  arrangement  of  the 
fascia  lata,  precisely  similar  to  what  takes  place  in 
forming  any  other  of  its  simple  sheaths.  The  fascia 
transversalis  j  oins  the  iliac  portion  of  the  pelvic  fascia; 
1st,  along  the  crista  ilii  and  Poupart's  ligament,  as  far 
as  the  outer  side  of  the  femoral  vessels;  i.  e.,  a  point 
midway  betweeen  the  ant.  sup.  spin,  process  of  the 
ilium  and  pubic  symphysis ;  and  2d,  from  the  outer 
edge  of  Gimbernaut's  ligament  to  the  pubis ;  a  trian- 
gular opening  is  thus  left,  its  base  corresponding  to  the 
outer  or  free  edge  of  Gimbernaut's  ligament,  its  apex 
t  o  the  middle  point  above  mentioned ;  its  anterior  side, 


CRURAL  FASCIA.  135 

being  the  inner  half  of  Poupart's  ligament,  its  poste- 
rior, the  attachment  of  the  pectineus  muscle.  The 
anterior  and  upper  part  of  the  femoral  sheath,  or  the 
cribriform  fascia,  is  connected  by  means  of  the  falci- 
form fold  to  the  fascia  transversalis  at  the  anterior 
transverse  half  of  the  triangle,  and  the  posterior  part 
of  the  sheath  to  the  fascia  pelvica,  at  the  posterior 
transverse  half;  the  femoral  vessels,  enclosed  in  a 
proper  sheath,  occupy  the  outer  part  of  this  canal, 
leaving  between  them  and  the  free  edge  of  Gimber- 
naut's  ligament  a  space  through  which  the  intestine 
makes  its  way.  This  space  only  extends  to  the  point 
where  the  saphena  vein  passes  through  the  cribriform 
fascia  to  join  the  femoral  vein,  and,  except  at  the 
inner  side  of  the  vessels,  the  ext.  sheath  firmly  adheres 
to  the  proper  sheath.  It  follows,  1st,  that  this  space 
is  the  real  crural  canal;  2d,  the  sac  cannot  descend 
lower  than  the  termination  of  the  saphena  vein ;  3d, 
the  upper  portion  of  the  cribriform  fascia,  being  the 
most  yielding,  is  pushed  before  the  sac,  which  will,  in 
consequence,  turn  upwards  over  the  edge  of  the  falx ; 
4th,  as  the  falx  is  connected  to  Gimbernaut's  liga- 
ment, the  division  of  one  will  tend  to  relax  both. 

The  fascia  lata  gives  a  sheath  to  the  sartorius  mus- 
cle, another  common  to  the  three  hamstring  muscles 
several  to  the  abductor  muscles,  a  very  strong  one  to 
the  tensor  femorism.  Superiorly,  the  anterior  portion 
of  the  fascia  lata  is  united  to  Poupart's  ligament,  &c., 
as  described ;  posteriorly,  it  adheres  to  the  crista  ilii, 
and  over  the  sacrum  to  the  posterior  lumbar  fascia. 
Below,  the  fascia  is  continued  over  the  knee-joint, 
forming  a  fibrous  capsule,  adherent  to  the  patella  and 
its  ligament,  the  femoral  condyles,  and  muscular  ten- 
dons. It  is  strengthened  on  the  inner  side  of  the  joint 
by  an  aponeurosis,  derived  from  the  vastus  internus. 

Crural  fascia,  continuous  with  the  fascia  lata.  This 
fascia  surrounds  the  leg;  it  is  particularly  strong  over 
the  extensor  muscle,  to  which  it  affords  some  extent 


136  PLANTAE   APONEUROSIS. 

of  attachment :  a  strong  septum  separates  the  exten- 
sors from  the  peroneal  muscles,  another  is  placed  be- 
tween the  latter  and  the  posterior  muscles.  The  fas- 
cia is  thus  subdivided  into  three  principal  sheaths; 
the  posterior  one  is  still  further  divided  by  a  strong 
fascia,  which  passes  transversely  between  the  super- 
ficial and  the  deep  set  of  muscles  and  posterior  tibi- 
al  vessels. 

Annular  ligaments.  At  the  ankle-joint  the  fascia  is 
strengthened  by  transverse  fibres ;  one  set  the  ant. 
ann.  lig.,  arises  from  the  ext.  part  of  the  calcaneum 
by  a  small  but  dense  extremity,  and,  expanding  as  it 
runs  inwards,  sends  a  branch  to  the  inner  malleolus, 
and  another  across  the  foot  to  the  inner  edge  of  the 
plantar  fascia ;  the  first  gives  a  sheath  to  the  tendon 
of  the  tibalist  ant.  and  common  extnsor  and  a  partial 
one  to  the  exten.  pollices.  The  second  branch  forms 
a  distinct  sheath  for  each.  A  second  set,  int.  annular 
ligament,  arises  from  the  internal  malicious,  and  ter- 
minates, broad,  into  the  inner  side  of  the  calcaneum, 
and  plantar  fascia.  The  third  set,  ext.  annular  liga- 
ment, extends  from  the  outer  malleolus  to  the  calca- 
neum. Distinct  sheaths  are  formed  for  the  tendons, 
vessels  and  nerves  passing  behind  each  malleolus.. 

The  dorsal  aponeurosis  of  the  foot  covers  the  dor- 
sum,  uniting  with  the  plantar  fascia  at  the  edges  of 
the  foot,  and  terminating  at  the  heads  of  the  metatar- 
sal  bones. 

The  plantar  aponeurosis  is  divisible  into  three  por- 
tions; the  middle  commences  at  the  inner  tuberosity 
of  the  calcaneum,  and  proceeds,  gradually  becoming 
broader,  to  the  heads  of  the  metatarsal  bones,  where 
it  divides  into  four  branches,  each  of  which  nearly  en- 
sheaths  the  corresponding  flexor  tendon,  and  is  in- 
serted into  the  edges  of  the  dorsal  expansion  of  the 
first  phalanges.  This  portion  sends  a  septum  on  each 
side,  which  separates  the  muscles  in  the  middle  from 
those  on  either  edge  of  the  sole  of  the  foot;  the  inner 


BRACHIAL   FASCIA.  137 

portion  covers  the  inner  muscles  of  the  foot;  it  arises 
from  the  int.  annular  ligament;  internally,  it  joins 
the  dorsal  aponeurosis,  and  externally,  the  internal 
septum;  the  outer  portion,  much  stronger,  covers  the 
muscles  on  the  outer  edge  of  the  foot;  it  arises  from 
the  calcaneum;  internally  it  joins  the  ext.  plantar 
septum,  and  externally  the  dorsal  aponeurosis;  it  is 
also  firmly  attached  to  the  base  of  the  fifth  metatarsal 
bone.  Numerous  septa  from  the  upper  surface  of  the 
plantar  fascia  pass  between  the  plantar  muscles  and 
tendons  to  be  attached  to  the  tarsal  and  to  the  edges 
of  the  metatarsal  bones. 

The  arm  and  shoulder  also  possess  aponeurotic  in- 
vestments. The  supra  spinatus,  intra  spinatus,  and 
subscapular  fossse  are  converted  into  osteo-fibrous 
cases  by  strong  aponeuroses,  from  which  the  respec- 
tive muscles  derive  attachments.  The  infra  spinatus 
apon.  bifurcates  to  enclose  the  deltoid ;  the  superfi- 
cial layer  joins  the  brachial  fascia,  and  the  deep  one 
is  attached  to  the  short  head  of  the  biceps. 

The  brachial  fascia  is  firmly  attached  to  the  mar- 
gins of  the  axilla,  and  appears  also  to  be  connected 
to  the  acromion  and  spine  of  the  scapula.  It  encloses 
the  arm,  and  is  continuous  below  with  the  fascia  of 
the  fore-arm;  the  majority  of  its  fibres  are  circular. 
Its  most  remarkable  processes  are,  1st,  int.  inter- 
muscular  septum,  which  is  attached  to  the  posterior 
lip  of  the  bicipital  groove  below  the  teres  major,  and 
the  inner  ridge  and  condyle  of  the  humerus  The  ex- 
ternal septum  commences  at  the  anterior  lip  of  the  bi- 
cipital  groove,  where  it  is  united  to  the  tendon  of  the 
deltoid,  and  is  firmly  attached  to  the  outer  condyloid 
ridge  and  condyle.  The  muscles  and  vessels  on  the 
anterior  and  posterior  part  of  the  arm  are  thus  en- 
closed by'(two  large  distinct  sheaths,  from  which  small 
ones  are  derived  for  each  muscle  or  vessel.  The  bra- 
chial vessels  and  median  nerve  have  a  single  sheath. 
The  apneurosis  of  the  fore-arm  is  strengthened  above 


138  PALMAR   FASCIA. 

by  the  expansion  of  the  biceps  tendon;  a  transverse 
septum  separates  the  superficial  from  the  deep  set  of 
muscles  on  the  anterior  part  of  the  arm.  A  similar 
septum  passes  between  the  superficial  and  the  deep- 
seated  extensor  muscles  on  the  back  of  the  arm. 

The  dorsal  annular  ligament  of  the  wrist  is  com- 
posed of  thin  parallel  fibres,  which  extend  from  the 
pisiform  bone  and  palmar  fascia  to  the  outer  edge  of 
the  radius.  It  forms  six  distinct  sheaths:  1st,  one 
for  the  tendons  of  the  extens.  os.  metacarpi  pollicis 
and  prima  internodii;  2,  radial  extensors;  3,  exten. 
secundi  internodii;  4,  exten.  communis  et  exten.  in- 
dicis;  5,  ext.  min.  digiti;  6,  exten.  carpi  ulnaris. 

The  ant.  annular  lig.  is  a  thick  fibrous  band  which 
arises  from  the  pisiform  and  unciform  bones,  and  is 
inserted  into  the  trapezium  and  scaphoid  bones. 
Most  of  the  muscles  of  the  thumb  and  little  finger 
arise  from  its  anterior  surface.  It  presents  a  partial 
sheath  for  the  tendons  of  the  flex.  carp,  rad.,  and 
only  one  for  the  tendons  of  the  flexor  muscles  and 
median  nerve. 

The  palmar  fascia  arises  from  the  ant.  annular  lig. 
and  tendon  of  the  palmaris  longus;  it  is  composed  of 
strong  diverging  fibres,  which  are  disposed  over  the 
muscles  and  tendons  in  the  middle  and  edges  of  the 
hand,  -precisely  as  the  plantar  fascia  in  the  foot. 

Composed  of  transverse  fibres,  there  is  a  dorsal 
fascia,  derived  from  the  dorsal  annular  ligament;  it 
covers  the  back  of  the  hand.  A  loose  but  elastic  cel- 
lular tissue  serves  the  purpose  of  synovial  sheaths 
for  the  extensor  tendons. 


139 


CHAPTER  VII. 

THE  VASCULAR  SYSTEM. 

UNDER  this  head  are  comprised  the  heart,  arteries, 
and  veins,  the  organs  for  the  circulation  of  the  blood ; 
and  the  lymphatics,  which  absorb  the  lymph  and  chyle^ 
and  convey  them  into  the  sanguineous  circulation. 

SECTION   I. 

THE  HEART 

is  of  a  flattened  conical  shape,  and  placed  in  an  ob- 
lique direction  between  the  two  lungs,  where  it  rests 
upon  the  central  tendon  of  the  diaphragm.  Its  base, 
turned  upwards  and  backwards,  lies  close  to  the 
spine,  and  its  apex  nearly  touches  the  fifth  and  sixth 
costal  cartilages  of  the  left  side :  its  edges  are  turned 
to  either  side.  The  division  of  the  heart  into  two 
auricles  and  two  ventricles  is  indicated,  1st,  by  a 
circular  furrow,  which  surrounds  the  heart  near  its 
base,  and  separates  the  auricular  from  the  ventricu- 
lar portions ;  and  2dly,  by  a  vertical  furrow,  which, 
after  dividing  the  former  portion  into  two  auricles, 
descends  on  the  anterior  and  posterior  surfaces  of 
the  latter  portion,  meeting  at  a  little  to  the  right  of 
the  apex.  The  anterior  surface  of  the  ventricular 
portion  is  unequally  divided  by  the  anterior  portion 
of  the  ventrical  furrow :  the  greater  part,  which  is  on 
the  right  of  the  furrow,  belongs  to  the  right  ventricle, 
the  smaller  to  the  left.  The  inferior  surface,  which 
rests  upon  the  diaphragm,  is  nearly  equally  divided 
by  the  posterior  furrow.  The  right  margin  of  the 
heart,  which  also  rests  on  the  diaphragm,  thus  forms 
a  part  of  the  right  ventricle ;  and  the  left,  thick  and 
round,  which  is  lodged  in  a  hollow  in  the  left  lung, 
forms  the  greater  part  of  the  left. 


140  LEFT   VENTRICLE. 

The  following  parts  present  themselves  from 
before  backwards  on  the  base  of  the  heart;  1,  the 
pulmonary  artery  and  infundibulum,  behind  which,  and 
at  first,  partly  concealed  by  them;  2,  the  arota;  3, 
the  circular  furrow ;  4,  the  two  auricles,  and  their 
appendages,  that  of  the  right  being  in  front,  and  the 
left  behind. 

The  right  ventricle  (anterior  and  inferior)  is  trian- 
gular ;  its  parietes,  which  are  thin  in  comparison 
with  those  of  the  left,  are  remarkable  internally  for 
their  reticulated  appearance,  which  is  produced  by 
the  intercrossing  of  the  carnese  columnse;  one  set  of 
these,  few  in  number,  is  attached  to  the  parietes  of 
the  ventricle  by  one  end  only,  and  by  the  other  to 
the  chordae  tendinese  and  auriculo  ventricular  valve ; 
the  second  by  both  ends ;  the  third,  in  their  whole 
length,  by  their  sides. 

The  auricular  orifice  posterior,  and  to  the  right  side 
of  the  base,  is  elliptical,  and  provided  with  an  auricu- 
lar membranous  fold  (tricusp id  valve,)  which  projects 
into  the  ventricle;  the  valve,  although  it  has  even  more 
than  three  angles,  is  really  mitral,  each  division  cor- 
responding to  the  ant.  and  post,  half  of  the  ellipsis. 

The  chordse  tendinese  arise  from  the  ends  of  the  first 
set  of  columns,  and  from  the  sides  of  the  ventricle, 
particularly  the  septum  cordis;  as  their  office  is  to 
tense  and  close  the  valves,  one  set  is  inserted  into  the 
under  surfaces  of  the  valves,  and  other  sets,  coming 
from  opposite  sides  of  the  ventricle,  cross  each  other 
to  be  inserted  into  the  edge  of  the  opposite  valve. 

The  orifice  of  the  pulmonary  artery  is  anterior,  and 
to  the  left  side  of  the  base,  and  separated  from  the 
auricular  orifice  by  a  portion  of  the  tricuspid  valve: 
it  is  guarded  by  three  folds  (sigmoid  valves,)  each  of 
which  presents  a  small  nodule  (corpus  aurantii)  in 
its  centre. 

Left  ventricle  (posterior  and  superior)  differs  from 
the  right;  first,  it  exceeds  the  latter  at  the  apex,  but 


RIGHT   AURICLE.  141 

is  embraced  by  it  at  the  base;  secondly,  it  is  conical 
and  uniformly  convex  ;  it  holds  somewhat  more  than 
the  right  (Cruveilhier,)  somewhat  less  (Bouillaud  ;) 
thirdly,  some  of  its  columns  are  bifurcated,  and  they 
enter  into  more  complex  union  with  each  other:  its 
sides  are  thicker  in  the  prop,  of  three  to  one ;  fourthly, 
the  valve  is  more  evidently  mitral,  and  the  right  half 
alone  separates  the  auricular  from  the  aortic  orifice; 
the  latter  has  three  valves,  like  those  of  the  pulmo- 
nary, but  the  two  orifices  are  so  near  each  other  that 
this  half  of  the  mitral  valve  and  the  adjoining  aortic 
valve  have  a  common  base. 

The  right  auricle  has  three  sides,  an  anterior,  poste- 
rior, and  that  formed  by  the  septum  auric.  It  has 
five  openings.  1.  the  auriculo  ventricular  ;  2,  that  of 
the  vena  cava  descendens,  which  looks  downwards  and 
slightly  backwards;  3,  that  of  the  vena  cava  inf., 
which  forms  a  right  angle  with  the  trunk  to  open  into 
the  auricle  close  to  the  septum  aur.,  through  the  post, 
side.  It  is  guarded  by  a  valve  (^Eustachian,)  which 
surrounds  the  anterior  half,  sometimes  two-thirds,  of 
the  orifice ;  one  extremity  seems  to  be  continuous 
with  the  annulus  ovalis,  the  other  is  lost  in  the  mar- 
gin of  the  orifice;  4,  that  of  the  coronary  vein;  this  is 
placed  before  the  latter,  and  separated  from  it  by  the 
Eustachian  valve  ;  it  is  provided  by  a  valve  (valvula 
Thesbesiana ;  5,  that  of  the  foramen  ovale,  or  rather 
the  fossa  ovalis,  bounded  above  and  in  front  by  a  semi- 
circular prominent  margm,improperlycalled&7zraw£ws. 
A  projecting  muscular  fasciculus,  said  to  be  the  seat 
of  a  tubercle  (tuber.  Loweri,)  separates  the  openings 
of  the  two  cavte  on  the  right  side  ;  another,  in  a  verti- 
cal direction,  divides  the  auricle  into  its  sinus,  which 
comprehends  these  openings,  and  its  proper  auricu- 
lar portion.  The  auricular  portion  presents  numer- 
ous vertical  muscular  fasciculi  (musculi  pectinati,) 
which  are  crossed  by  smaller  oblique  fibres,  so  as  to 
give  the  surface  a  reticulated  appearance.  The  for- 


142  STRUCTURE   OF   HEART. 

amina  (Thebesii)  seen  in  this  auricle  are  small  ori- 
fices of  a  few  areolar  spaces. 

The  left  auricle  differs  from  the  right;  1,  it  is 
somewhat  less  capacious;  2,  in  shape  it  is  an  irre- 
gular cuboid ;  3,  the  auriculo  ventricular  orifice  is 
less  in  size;  4,  it  has  four  venous  openings  (pulmo- 
nary) without  valves,  two  opening  on  the  right  side 
and  two  on  the  left ;  5,  it  communicates  only  by  a  nar- 
row orifice  with  its  appendix ;  6,  it  presents  no  ves- 
tige of  fossa  ovalis,  unless,  which  is  sometimes  the 
case,  the  two  auricles  still  communicate  by  a  narrow 
oblique  canal. 

Structure  of  the  heart.  The  basement  or  skeleton 
of  the  heart  is  formed,  1,  by  two  fibrous  zones,  which 
constitute  the  auriculo  ventricular  orifices,  and  send 
expansions  into  the  mitral  and  tricuspid  valves ;  2, 
by  two  arterial  zones,  which  in  the  same  way  surround 
the  arterial  orifices,  and  send  expansions  into  the 
sigmoid  valves,  and  three  thin,  but  strong  processes, 
which  fill  up  the  intervals  between  the  three  festoons 
at  the  base  of  each  artery,  and  strengthen  their  at- 
tachment to  the  ventricles.  These  two  auriculo  ven- 
tricular orifices  are  closely  united  in  the  same  plane, 
and  the  aortic  orifice,  placed  in  their  angle  of  separa- 
tion in  front,  is  confounded  with  them  in  its  posterior 
half.  This  point  is  occupied  by  a  cartilaginous  or 
even  osseous  arch  (os  cordis)  in  some  animals.  The 
pulmonary  orifice  is  anterior  to,  and  five  or  six  lines 
higher  than  the  latter. 

The  muscular  portion  of  the  heart  arises  from  these 
zones.  The  ventricular  fibres  are  separable  into  three 
distinct  layers.  The  middle  layer  forms  a  distinct 
conical  tube,  open  at  both  ends,  for  each  ventricle  ; 
the  ventricular  septum  is  formed  by  their  adossement. 
The  outer  layer,  common  to  both  ventricles,  descends 
in  a  spiral  direction;  those  covering  the  right  ventricle 
to  the  left,  and  those  on  the  left  ventricle  to  the  right, 
as  far  as  the  apex.  The  two  layers,  twisting  half 


INVESTMENTS   OF   HEART.  143 

round  each  other,  now  enter  the  openings  at  the  apex 
of  each  tube  formed  by  the  middle  layer,  and  divide 
into  two  sets  to  form  the  inner  layer  of  each  ventricle. 
The  first  set  pass  upwards,  to  line  the  opposite  side 
of  the  ventricle,  and  the  second,  variously  contorted, 
ascend  on  the  same  side  ;  in  both  cases  those  fibres 
which  were  superficial  in  the  outer  layer  become 
the  deep-seated  in  the  inner  one.  The  columnse 
carnese  seem  to  be  made  up  of  portions  of  the  first, 
and  of  spiral  fibres  of  the  second  set. 

Auricular  fibres.  A  common  layer  extends  trans- 
versely across  the  anterior  surfaces  of  both  auricles. 
Of  the  layer  proper  to  each  auricle,  a  circular  set  of 
fibres  is  seen  near  the  auriculo  ventricular  openings, 
and  a  second  set,  running  an  oblique  course,  is  ar- 
ranged in  arches,  which  are  fixed  by  their  ends  to  the 
ventricular  zones,  their  free  portions  surrounding  the 
venous  orifices,  and  projecting  between  them.  The 
annulus  ovalis  is  formed  by  some  muscular  arches  of 
the  septum.  If  the  common  ventricular  fibres  be  cau- 
tiously cut  through  at  the  vertical  furrow,  the  ventri- 
cular tubes  may  be  separated  from  each  other  entire. 

Development.  At  an  early  period  of  conception, 
the  heart  fills  the  thoracic  cavity,  and,  up  to  three 
months,  its  direction  is  vertical,  and  its  shape  round 
and  symmetrical.  The  ventricles  are  very  minute, 
and  the  right  auricle  in  size  equals  the  rest  of  the 
organ;  subsequently  its  four  cavities  are  nearly  equal. 
The  auricular  septum  is  wanting,  and  the  ventricu- 
lar is  deficient  at  its  upper  part ;  the  auricles  after- 
wards communicate  by  the  foramen  ovale,  and  the 
ventricles  indirectly  by  the  ductus  artenosus.  The 
Eustachian  valve  covers  part  of  the  orifice  of  the 
sup.  cava,  as  well  as  that  of  the  lower  one  (Martin 
St.  Ange;)  as  development  proceeds,  the  foramen 
ovale  is  gradually  closed  by  a  membrane,  and  the 
Eustachian  valve  diminishes  in  the  same  proportion. 

The  heart  is  enclosed  in  two  distinct  investments, 


144  ARTERIES    OF    HEART. 

1.  The  fibrous  pericardium.     This  membrane   ia 
formed  of  aponeurotic  fibres  ;  it  is  conical  in  shape, 
its  base  corresponding  to  the  tendon  of  the  dia- 
phragm, to  which  it  adheres  in  the  adult;  its  apex 
surrounds  the  origins  of  the  large  vessels,  upon  which 
it  is  gradually  lost.     Its  size  is  said  to  equal  that  of 
the  heart  in  the  greatest  state  of  distention. 

2.  The  serous  pericardium.     A  complete  sac  of  se- 
rous membrane  which  lines  the  former  envelope, 
and  is  reflected  from  it  on  the  great  vessels  and 
heart ;  it  passes  up  on  the  former  to  some  distance, 
especially  on  the  aorta  and  pulmonary  art.,  least  on 
the  inf.  vena  cava. 

The  endocardium  (Bouillaud)  is  a  white  pellucid 
membrane,  resembling  the  arachnoid;  it  lines  the 
cavities  of  the  heart,  covers  the  valves  and  tendinous 
cords,  and  is  continuous  with  the  inner  coat  of  the 
arteries.  In  the  neighborhood  of  the  zones  and  in 
some  of  the  areolse  of  the  auricles,  it  comes  into  con- 
tact with  the  serous  pericardium.  The  valves  of 
the  heart  are  formed  by  folds  of  this  membrane, 
with  a  little  fibrous  tissue  at  their  free  margins. 
The  aortic  and  pulmonary  valves  are  named  semilunar 
and  present  each,  in  the  centre  of  its  free  margin,  a 
slight  eminence,  the  corpus  aurantii. 

The  heart  is  supplied  with  blood  by  the  coronary 
arteries.  These  arise  from  the  aorta,  immediately 
above  its  opening  and  behind  the  aortic  valves;  the 
right  supplies  the  right  auricle,  the  posterior  part  of 
the  ventricles,  and  the  thin  edge  of  the  heart;  it  sinks 
into  the  right  auriculo  ventricular  groove,  winds  round 
to  the  back  of  the  heart,  sends  a  long  branch  along 
the  anterior  thin  edge  of  the  heart,  runs  along  the 
groove  on  the  posterior  surface,'and  terminates  by  in- 
osculating with  the  left;  this  supplies  the  left  auricle, 
left  ventricle,  and  septum.  One  branch  runs  in  the 
left  auriculo  ventricular  groove,  the  others  along  the 
anterior  surface  of  the  heart,  opposite  the  septum  and 


THE    AORTA.  145 

terminates  near  its  apex  by  inosculating  with  the 
right.  The  coronary  veins  terminate  by  one  large 
opening  in  the  right  auricle,  between  the  Eustachian 
valve  and  auriculo-ventricular  opening.  A  few  veins 
open  directly  by  small  apertures  into  the  right  auri- 
cle. 

The  heart  is  supplied  with  nerves  from  the  cardiac 
plexus.  This  is  formed  by  branches  from  the  sympa- 
thetic, the  par  vagum,  and  recurrent  nerves.  It  gives 
off  the  coronary  plexuses  to  accompany  the  arteries, 
and  terminates  in  the  muscular  tissues  of  the  heart. 

SECTION  II. 
THE  ARTERIES. 

PULMONARY  ARTERY,  Or.  from  the  circulus  arteri- 
osus  of  the  right  ventricle,  which  at  this  point  dilates 
into  a  kind  of  infundibulum.  At  first  in  front  of  the 
aorta,  between  the  two  auricles,  it  crosses  to  its  left 
side,  and  divides  into  its  two  pulmonary  branches; 
the  right,  an  inch  and  a  half  long,  passes  under  the 
arch  of  the  aorta,  behind  the  descending  cava,  and 
in  front  of  the  bronchus  ;  and  the  Ireft,  an  inch  long, 
in  front  of  its  descending  portion  and  left  bronchus, 
and  behind  the  pulmonary  veins.  It  is  attached  to 
the  heart,  1st,  by  its  inner  tunic;  and  2dly,  by  pro- 
longations from  the  arterial  zones,  which  are  attached 
to  the-  convex  edges  of  its  three  festoons,  and/  to  the 
edges  of  their  angular  intervals.  The  fibrous  peri- 
cardium covers  the  greater  part  of  its  two  branches. 

AORTA,  Or.  in  the  same  manner  as  the  pulmonary 
artery,  immediately  behind  that  vessel,  in  the  anterior 
triangular  interval  formed  by  the  ventricular  zones. 
The  arch  commences  from  this  point,  which  is  oppo- 
site to  the  upper  edge  of  the  fourth  costal  cartilage  of 
the  left  side,  where  it  joins  the  sternum,  and  coming 
forwards  ascends  to  the  upper  edge  of  the  second  cos- 
tal cartilage  on  the  right  side;  2,  it  passes  horizon- 
13 


146  CORONARY   ARTERIES. 

tally  backwards  on  a  level  with  the  junction  of  the 
first  with  the  second  bone  of'the  sternum  to  the  left 
side  of  the  body  of  the  second  dorsal  vertebra;  3,  it 
lastly  descends,  still  inclining  backwards,  to  the  same 
side  of  the  third  or  fourth  dorsal  vertebra,  under  the 
name  of  thoracic  aorta,  continues  this  course,  coming 
more  and  more  in  front  of  the  spine,  enters  the  abdo- 
men through  the  aortic  opening  of  the  diaphragm, 
and,  finally,  as  the  abdominal  aorta,  it  passes  to  the 
body  of  the  fourth  lumbar  vertebra,  where  it  divides 
into  the  two  common  iliac  and  middle  sacral  arteries. 
Relations  of  the  arch.  Within  the  pericardium, 
which  reaches  its  transverse  portion,  the  artery  is, 
first,  immediately  behind  the  infundibulum  of  the 
right  ventricle,  and  the  pulmonary  artery  ;  it  then 
gets  to  the  right  side  of  this  vessel,  and  to  the  left 
of  the  vena  cava  descendens.  Its  transverse  and  de- 
scending portions  form  an  arch  over  the  root  of  the 
left  lung ;  its  transverse  portion  is  partially  covered 
by  the  left  vena  innonjinata;  it  rests  on  the  bilfur- 
cation  of  the  trachea  posteriorly.  The  phrenic  and 
vagus  nerves  descend  on  each  side,  the  left  vagus  a 
little  in  front  of  it.  Its  recurrent  branch  hooking 
round  it  where  it  is  joined  by  the  ductus  arteriosyis. 

The  primary  Branches  of  the  Aorta. 

From  the  arch;  1,  2,  coronary  arteries,  3,  A.  inno- 
minata,  4,  left  common  carotid,  5,  left  subclavian. 

From  the  Thoracic  portion  ;  6,  intercostales,  7,  Bron- 
chiales,  8,  cesophageal,  9,  mediastinal. 

From  its  abdominal  portion  ;  10,  Phrenicse,  11,  cod- 
iac,  12,  sup.  mesenteric,  13,  inf.  mesenteric,  14,  capsula- 
ares,  15,  renales,  16,  spermatic,  17,  lumbar,  18,  common 
iliac,  19,  sacram.edia. 

Art.  Coronaria  have  just  been  described. 
1st  set  from  the  convexity  of  the  arch. 


LEFT    COMMON    CAROTID.  147 

ART.  INNOMINATA, 

from  an  inch  to  an  inch  and  a  half  in  length,  arises 
from  the  summit  of  the  arch,  passes  upwards,  for- 
wards, and  to  the  right  side,  and  divides  opposite  the 
right  sterno-clavicular  artic.  into  the  right  com.carot. 
and  the  subclavian  trunks.  Red,  behind,  the  trachea 
and  right  pleura,  before  right  vena  innom.,  sterno- 
hyoid  and  thyroid  m.  upper  bone  of  the  sternum. 

RIGHT  COMMON  CAROTID. ' 

This  art.  passes  from  its  origin  upwards,  forwards, 
and  a  little  outwards  in  the  neck,  along  the  inner 
edge  of  the  sterno-mastoid  nerve,  until  it  arrives  at 
the  upper  border  of  the  thyroid  cartilage,  and  di- 
vides into  its  terminal  branches,  the  ext.  and  int. 
carotid  arteries.  In  its  first  stage  it  lies  in  the  ant. 
inf.  triangle  of  the  neck ;  it  is  here  covered  by  the 
skin,  platysma,  and  partially  by  the  sterno-mastoid 
externally,  the  sterno-hyoid  and  thyroid  internally  ; 
it  is  enclosed  in  the  carotid  sheath,  lying  internally 
to  the  vagus  nerve  and  int.  jug.  vein,  behind  it  are 
the  sympathetic  and  recurrent  nerves.  In  its 
second  stage  this  art.  lies  in  the  ant.  sup.  triangle 
of  the  neck,  and  is  covered  only  by  the  skin,  platy- 
sma, and  fascia ;  its  other  relations  are  similar  to 
those  in  the  first  stage. 

LEFT  COMMON  CAROTID. 

Arises  from  the  arch  of  the  aorta  within  the  thorax, 
it  is  here  covered  by  the  left  vena  innom.  and  the 
origins  of  the  sterno-hyoid  and  thyroid  muscles,  to 
its  inner  side  is  the  trachea,  to  its  outer  the  left  sub- 
clavian and  cone  of  the  pleura,  behind  it  is  the  tho- 
racic ducfand  oesophagus.  In  the  neck  it  is  similar 
in  course  and  relations  to  the  right  com.  carotid, 
with  the  exception  of  its  connection  with  the  oeso- 
phagus and  thoracic  duct. 

The  right  and  left  com.  carotids  differ  in  their  ori- 


148  FACIAL    ARTERY. 

gin,  length,  and  a  few  of  their  relations,  as  just  de- 
scribed. The  terminating  branches  of  the  com.  caro- 
tid art.  are  the  external  and  internal  carotid  arteries. 
EXT.  CAROTID.  Ascends  inwards  and  forwards  to 
the  submaxillary  gland;  then  backwards,  imbedded 
in  the  parotid  gland,  parallel  to  and  behind  the  ramus 
of  the  jaw,  as  high  as  the  neck  of  the  condyle.  Rel. 
ext.  integuments  and  platysma ;  the  digastric  and 
stylo-hyoid  m.  and  ninth  nerve  ;  the  seventh  nerve, 
int.  the  stylo-glossusandpharyngeus  m.  which  sepa- 
rate it  from  the  int.  carotid  Ram.  10  in  no. 

Anterior  Set. 

Thyroid  superior,  Or.  opposite  the  cornu  of  the  os 
hyoides.  It  runs  below  this  cornu,  and  the  lingual 
nerve,  and  upon  the  sup.  laryngeal  nerve.  Ram. 
1,  hyiodeus,  cellular  membrane  between  the  stylo- 
hyoid  muscle;  2,  superficiales,  sheath  of  the  carot., 
glands,  and  sterno-mastoid  muscle ;  3,  laryngeus, 
larynx,  epiglottis;  a  branch  descends  on  the  crico- 
thyr.  memb. ;  4,  thyroideus,  generally  three,  to  the 
thyroid  gland. 

Lingualis,  runs,  1st,  horizontally  above  the  cornu 
of  the  os  hyoides;  2d,  vertically,  to  the  base  of  the 
tongue;  and  3d, horizontally,  as  the  Ranine  artery, 
to  its  tip.  Ram.  4.  1,  hyoideus  supra  hyoid  muscles, 
epiglottidean  glands;  2,  dorsalis  linguse,  dorsum  of 
the  tongue,  tonsil,  pal.  arches,  &c. ;  3,  sublingualis, 
sublingual  gland,  mucous  membrane;  4,  Ranine, 
along  the  outer  side  of  the  genio  gloss,  m.  to  the  tip 
of  the  tongue. 

Facialis,  upwards  and  inwards  to  the  submax. 
gland,  forwards  on  the  upper  edge  of  the  gland,  and 
upwards  from  the  ant,  edge  of  the  masseter  to  the 
labial  commissure,  alanasiand  inner  canthus  of  the 
orbit.  Ram.  6.  1,  Inf  palatine,  ascends  between 
the  stylo  gloss,  and  pharyngeus  to  the  sup.  constrictor 
tonsil,  velum,  &c.  2,  Tonsillaris,  between  the  stylo 


INTERNAL  MAXILLARY  GLANDS.         149 

gloss,  and  int.  pteryg.  m.  to  the  tonsil ;  3.  Glandu- 
lares,  to  submaxillary  gland;  4,  Submentalis  runs 
close  under  the  jaw,  to  the  muscles  at  the  symphysis 
menti;  5,  abialis.  inferior,  lower  lip  and  chin;  6, 
Coron.  inferior,  mucous  membrane  of  the  lower  lip 
and  labial  glands;  7,  Masseteric,  masseter,  buccina- 
tor; 8,  coronaria  sup.,  mucous  membrane  of  the 
upper  lip  and  labial  glands;  9,  nasi  later alis,  side  of 
the  nose  in  numerous  anastomoses ;  10,  angularis 
lacrymal  sac,  orbicularis  muscle. 
Posterior  Set. 

Sterno-mastoid,  to  that,  and  to  the  adjoining  mus- 
cles and  glands. 

Occipitttlis,  ascends  parallel  to,  and  concealed  by, 
the  post,  belly  of  the  digastric ;  passes  between 
the  transverse  process  of  the  atlas  and  mastoid 
process ;  and  then  upon  the  recti  beneath  the  other 
cervical  muscles  which  it  lastly  perforates  at  the 
centre  of  the  sup.  transverse  ridge.  Ram.  1 ,  mastoid; 
2,  post  meningeal;  3,  cervicalis  descendens,  which  de- 
scends between  the  splenius  and  complexus;  4, 
parietal,  parietal  foramen;  and  5,  terminal,  upon  the 
back  of  the  cranium. 

Posterior  auris,  Ram,  auricular,  muscular,  parotides, 
and  stylo -mastoid,  which  passes  through  the  Fallopian 
canal,  to  the  tympanum  and  labyrinth. 
Inner  Set  of  Branches. 

Pharyngea  Ascendens  ascends  deeply  by  the  side 
of  the  pharynx ;  Ram.  pharyngeal,  to  the  pharynx, 
tonsils,  and  palatine  arches,  post,  meningeal,  through 
the  post,  foramen  lacerum;  ant.  meningeal,  ant.  fora- 
men lacerum ;  Eustachian,  to  that  tube,  and  to  the 
tympanum. 

Terminal  Set  of  Branches. 

Trans,  faciei,  runs  a  little  below  the  zygoma  to  an- 
astomose on  the  face  with  the  other  facial  branches. 

Internal   maxillary  passes  1,  inwards  behind  the 
18* 


150  OPTIIALMIC    ARTERY. 

neck  of  the  jaw  ;  2,  upwards  and  inwards,  in  a  space 
bounded  by  the  two  ptcrygoidei  m.,  the  buccinator 
and  the  ramus  of  the  jaw ;  3,  horizontally,  forwards 
between  the  heads  of  the  pteryg.  ext.  across  the 
pteryg.  maxillary  fossa  to  the  infra  orbitar  canal 
Ram.  first  part  of  its  course;  1,  Art.  meningea  media 
magnet,  through  the  foramen  spinale ;  ramus  hiatus 
Fallopii  to  the  facial  nerve;  2,  Infra  dental,  Ram. 
mylo-hyoid,  to  that  muscle,  and  labial  glands. 

Second  Order. 

3,  Deep  temporal,  two  to  the  deep  surface  of  them, 
4,  Massetericse ;  5,  Pterygoidei;  6,  Buccales ;  7,  Supra 
dental,  roots  of  the  post,  teeth,  and  antrum. 

Third  Order; 

8,  Infra  orbitar  (terminal)  antrum,  ant.  alveoli,  and 
face ;  9,  palatina  descendens,  pos.  palatine  canal, 
palate,  ram.  incisivus ;  10,  Nasalis,  spheno-palatine 
foramen,  and  nose,  ram.  nerve.  Cotunnius;  11,  videan, 
pterygoid  foramen,  to  accompany  the  nerve. 

Temporalis ;  Ram.  1,  auricular,  capsule  of  the  jaw; 
2,  Terminal,  temporaries,  anterior,  media  et  posterior. 

INT.  CAROTID,  runs  upwards,  vertically,  to  the 
foramen  caroticum,  forwards  along  the  canal,  tor- 
tuous, through  the  cavernous  sinus,  vertically,  by 
the  side  of  the  anterior  clinoid  processes.  Rel.  Int. 
side  of  the  pharynx,  tonsil,  symph.  nerve;  ext. 
pneumogastric  glossopharyngeal,  and  ninth  nerves; 
int.  jugular  vein;  post.  vert,  column;  ant.  stylo 
gloss,  et.  pharyngeus  m.  Internal  to  all  the  nerves 
in  the  cavernous  sinus.  Ram. 

A,  Opthalmic  passes  with  the  nerve  through  the 
foramen  opticum.  In  its  passage  through  the  orbit 
it  lies  1,  on  the  outside  of  the  nerve,  2,  on  its  upper 
part,  3,  on  its  inside.  Ram.  first  part  of  its  course; 
1,  Lacrymal  to  the  gland,  palpebra,  some  pierce  the 
os  mala ;  2,  Centralis  Retina,  centre  of  the  optic  nerve 


POSTERIOR  CEREBRAL  ARTERY.    151 

and  vitreous  humour,  to  the  posterior  surface  of  the 
lenticular  capsule. 

Second  Part  of  its  Course. 

3,  Supra  orbatilis,  through  the  supra  orbitar  notch 
to  the  forehead ;  4,  ciliary  posterior,  15  to  20,  through 
the  sclerotic  coat,  to  the  choroid  coat,  ciliary  pro- 
cesses, and  to  the  larger  circle  of  the  iris;  5,  ciliary 
long,  two  in  no.,  anas,  in  circles  on  the  post,  surface, 
and  smaller  circle  of  the  iris;  6,  muscular,  superior 
and  inf.  Ram.  ciliary  anterior,  to  the  larger  circle 
of  the  iris,  arid  conjunctiva. 

Third  Part  of  the  Opthal.  Art. 
7,  Ethmoidal  posterior  ;  through  the  post.  For.  Eth. 
to  the  dura   mater,  and  nasal  fossae;    8,  Ethmoidal 
anterior;  ant.  For.  Eth.  to  the  frontal  sinus,  nares; 
9,  Palpebral,  superior  et  inferior. 

Termination  of  the  Opth.  Art. 

10,  Nasal,  anastom.  with  the  term,  branch  of  the 
facial;  11,  Frontal,  to  the  inner  part  of  the  forehead. 

Art.  communicans  post.  (Willis)  runs  backwards, 
along  the  outer  side  of  the  pituitary  gland  and  corp. 
mamil.,  to  join  the  post,  cerebral  artery,  which  is  a 
branch  of  the  Basilar. 

Choroid,  backds.  and  outds.  along  the  optic  'fascic., 
enters  the  lat.  vent,  through  the  great  fissure,  and 
is  lost  in  the  choroid  plexus. 

Ant.  cerebral,  anastomoses  with  its  fellow,  by 
means  of  the  art.  communicans  ant.  and  then  runs, 
from  before  backwards,  on  the  upper  surface  of  the 
corpus  callosum  ;  supplies  the  hemispheres. 

Middle  cerebral,  in  the  fissure  of  Sylvius,  to  the 
ant.  and  .middle  lobes. 

Cereb.  Branches  from  the  Art.  Basil. 
Post  Cerebral,  to  the  Thalami,  Tuberc.     Quadri- 


152  SUBCLAVIAN   ARTERY. 

gemina.  etc.  It  is  joined  by  tlie  cornmunicans  of 
Willis. 

Ant.  Ccrebellar  super,  surface  of  the  cerebellum. 
Ram.  Int.  auditory,  through  the  int.  meatus  to  the 
internal  ear. 

Post.  Cerebellar,  sometimes  arises  from  the  verte- 
bral: passes  between  the  origins  of  the  ninth  pair 
of  nerves,  and  just  in  front  of  those  of  the  eighth,  to 
the  post,  part  of  the  cerebellum. 

SUBCLAVIAN  ARTERY 

extends  from  its  origin  to  the  lower  edge  of  the  first 
rib ;  it  runs,  1st,  upwards  and  outwards  to  the 
scaleni;  2d,  horizontally  between  them;  3d,  down- 
wards and  outwards  to  its  termination,  Rel.  before  it 
reaches  the  scaleni. 

The  Right,  1,  Ant.  sterno.  clavic.  artic.  ;  parallel 
to  the  subclavian  vein  where  it  joins  the  jugular; 

2,  crossed  by  the  phrenic  and  vagus  nerves  ;   3,  post. 
recurrent  nerve ;  pleura :  surrounded  by  filaments 
of  the  sympathetic  nerve. 

The  Left,  differs,  1,  Ant.  its  crossed  by  the  subc. 
vein;  2,  the  phrenic  and  vagus  are  parallel  to  it; 

3,  it  is  nearer  the  clavicle  than  the  spinal  column; 

4,  in  more  extensive  contact  with  the  cone  of  the 
pleura  and  lung. 

The  thoracic  duct  ascends  between  it  and  the  left 
carotid,  it  is  larger  than  the  right,  and  is  more 
deeply  seated  in  its  first  course. 

In  the  root  of  the  neck,  before  passing  behind  the 
scalenus  antic,  muscle,  the  subclav.  art.  are  covered 
by  the  skin,  platysma,sterno-mastoid  and  sterno-hyoid 
muscles  and  cervical  fascia ;  this  is  the  first  stage. 

Second  Part. — Between  the.  scaleni ;  the  brachial 
plexus  above  and  posterior,  and  the  first  rib  below, 
the  cone  of  the  pleura  behind  ;  the  ant.  scalenus  sepa- 
rates it  from  the  vein.  Third  Part. — Lies  in  the  pos- 
terior inf.  triangle  of  the  neck  covered  by  the  skin, 


t  THYROID    ARTERY.  153 

platysma,  and  a  quantity  of  loose  cellular  tissue,  the 
ext.  jug.  vein  descends  in  front  of  it,  and  its  own 
vein  lies  ant.  and  inf.  to  it ;  the  brachial  plexus  lies 
above  and  behind,  and  the  first  rib  immediately  pos- 
terior to  it.  Ram. 

First  Part  of  its  Course. 

Art.  vertebral,  (always  the  first  branch,)  runs 
through  the  transverse  foramina  of  the  cervical  ver- 
tebras, from  the  sixth  (sometimes  fourth)  to  the  se- 
cond, passes-  outwards  to  reach  that  of  the  first,  and 
winds  horizontally  backwards,  in  a  groove  behind 
its  artic.  process;  pierces  the  post,  occip.  atloidean 
lig.  beneath  the  suboccipital  nerve,  and,  proceeding 
forwards  and  upwards  through  the  foramen  magnum, 
inclines  to  its  fellow  on  the  ant.  surface  of  the  medul. 
oblongata.  It  lastly,  unites  with  it  at  the  pons  to 
form  the  Art.  Basilaris.  Ram.  1  and  2,  anterior  and 
posterior  Medulla  spinalis.  3,  Basilar  art.,  extends 
the  whole  length  of  the  pons  Varolii. 

Internal  mammary  arises  opposite  the  last,  descends 
in  the  thorax  behind  the  costal  cartilages,  close  to 
the  sternum,  to  the  xiphoid  cartilage.  Rel.,  crossed 
by  the  phrenic  nerve  which  then  lies  on  its  inner  side. 
Ram.  1,  ant.  intercostal,  5,  to  the  five  superior  inter- 
costal spaces  ;  2,  mediastinal,  thyrnicce,  glandulares, 
muscular,  &c.;  3,  Comes,  nervi  phrenicse,  runs  with 
the  nerve  to  the  diaphragm.  It  terminates  in  4, 
musculo-phrenicse,  diaphragm  and  inf.  intercostal 
spaces;  5,  abdominales,  anas,  with  the  epigastric 
and  lumbar  art. 

Thyroid,  an  axis  of  three  branches;  1,  Thyroid 
inf.  or  ascendens,  ascends  behind  the  carotid  sheath 
to  the  thyroid  gland;  2,  cervicalis  ascendens,  ascends 
on  the  ant.  scalenus,  parallel  to  the  phrenic  nerve ; 
3,  supra  scapularis,  or  transversalis  humeri,  to  the  su- 
pra scapular  notch.  Ram.  supra  acroniial,  supra 
spinalis,  and  infra  spinalis. 


154          THORACICA    STJPREMA   ARTERY.        . 

Transversalis  colli,  across  the  neck  above  the  trans, 
humeri.  Ram.  1,  cervical  super/,  to  the  fascia,  lym- 
phatic glands,  &c.  2,  scapularis post,  (terminal)  post, 
angle,  crista  and  inf.  angle  of  the  scapula. 

Second  Part  of  the  Subclav.  Art. 

Cervicalis  profunda,  passes  between  the  6  and  7 
cervical  transverse  processes,  and  ascends  deeply  in 
the  spinal  groove ;  anas,  with  the  occipital  and  ver- 
tebral art. 

Inter costalis  sup.  descends  on  the  outer  side  of  the 
first  thoracic  ganglion;  Ram.  2,  one  to  the  first,  and 
one  to  the  second  intercostal  space. 

AXILLARY  ARTERY 

Extends  from  the  infer,  edge  of  the  first  rib  to  the 
lower  margin  of  the  latissiinus  dorsi  and  teres  mus- 
cles; it  is  divided  into  three  stages  by  the  pectoralis 
minor,  which  crosses  in  front,  of  it.  Rel.  Ant.  Pect. 
major  above  and  below;  pectoralis  minor  in  middle 
post,  a  cellular  space,  then  teres  major  and  latissimus 
dorsi  m.;  Ext.  coracoid  process,  subscapularis  m. 
and  head  of  the  humerus:  int.  first  intercostal  space-, 
skin  of  the  axilla.  The  vein,  first  at  some  distance 
on  its  inner  side,  gets  nearer  and  more  anterior  to 
it  in  descending.  The  brachial  plexus,  first  on  its 
outer  side,  gradually  embraces  it;  the  inner  root  of 
the  median,  the  int.  cut  an.  and  ulna  nerves,  are  given 
off  on  its  inner  side;  the  ext.  cutan.  and  outer  root  of 
the  median  on  its  inner  side;  the  nmsculo  spiral, 
and  circumflex  nerves,  behind  it.  Ram.  At  the 
upper  edge  of  the  pectoralis  minor. 

Thoracica  acromialis  (constant. )  Ram.  Pectorales 
acromialis,  deltoidean ;  a  branch  separates  the  del- 
toid from  the  pectoralis  major  m. 

Thoracica  suprema  (irregular,)  ramifiesbetween  the 
pectoral  muscles ;  anas,  with  the  int.  mammary  art. 


SUPERIOR  PROFUNDA  ARTERY.    155 

Thoracica  alaris  (irreg.)  to  the  eel.  tissue  and 
glands  in  the  axilla. 

Below  the  pect.  minor. 

Thoracica  longa  (const.)  descends  parallel,  and 
close  to  the  lower  edge  of  the  pector.  minor  m.,  be- 
tween the  p.  major  and  serratus  magnus,  to  the  side 
of  the  thorax. 

Subscapularis  runs  along  the  lower  edge  of  the  sub- 
scapular  m.  accompanied  by  the  subscap.  nerve,  to 
the  inf.  angula  of  the  scapula.  Ram.  1,  Dorsalis 
scapulse,  through  the  triangular  opening  formed  by 
the  long  head  of  the  triceps,  teres  major,  and  edge 
of  the  scapula,  to  the  subscapular  fossa. 

Post,  circumflex  *)  encircle  the  surgical  neck  of  the 

Ant.  circumflex  jhumerus.  Ram.  1,  Deltoidean; 
2,  artic.  which  ascends  in  the  bicipital  groove. 

BRAOHIAL  ARTERY. 

Extends  from  the  termination  of  the  preceding  to  the 
bend  of  the  arm,  in  a  line  from  the  centre  of  the 
axilla  to  the  middle  of  the  latter;  Rel.  1,  in  the  arm: 
Ant.  inner  edge  of  the  coraco  brachialis  and  biceps, 
which  overlap  it ;  Post,  triceps,  brachialis  anticus  and 
musculo  spiral  nerve.  Int.  ulner  nerve  and  inf.  pro- 
fund,  art.  Ext.  coraco  brachialis,  cellular  interval 
between  the  brachialis  antic,  and  biceps.  The  median 
nerve,  first  on  its  outer  side,  crosses  at  about  its  mid- 
dle to  lie  on  its  inner  side;  2,  Rel.  at  the  elbow ;  Ant. 
expansion  of  the  biceps,  skin,  basilic  vein,  Post,  mid- 
dle of  the  brachialis  anticus,  Int.  median  nerve,  Ext. 
tendon  of  the  biceps,  Ram. 

Prof unda  Sup.  descends  in  the  spiral  groove  round 
the  posterior  surface  of  the  huinerus  to  anas,  with  the 
radical  recurrent  in  the  groove  between  the  brachialis 
antic,  and  supinator  longus,  Ram.  1,  descends  to  the 
inner  part  of  the  elbow-joint;  2,  to  accompany  the 
deep  branch  of  the  spiral  nerve ;  3,  musculares. 


156  RADIAL   ARTERY. 

Profunda  Ins.  descends  on  the  inner  side  of  the 
arm  along  with  the  ulnar  nerve  to  anas,  with  the 
post,  ulnar  recurrent,  between  the  int.  condyle  and 
olecranon  process.  Ram.  musculares. 

Anastomotica  Magna,  anas,  super,  with  the  inf.  pro- 
funda,  and  inf.,  with  the  ant.  and  post,  ulnar  re- 
current. 

Art.  Nutritia  humeri;  i.  e.  Terminal,  Radial,  and 
Ulnar  arteries. 

The  brachial  art.  is  superficial  throughout,  being 
covered  only  by  the  skin  and  fascia,  and  in  the  centre 
by  the  inner  edge  of  the  biceps,  nervous  filaments 
from  the  int.  cut.  and  nerves  of  Wrisberg  He  over 
it;  it  is  accompanied  by  the  brachial  vein  which  lies 
to  its  inner  side.  Below  the  bend  of  the  elbow  it 
sinks  into  a  triangular  fossa,  bounded  by  the  brach. 
antic,  above,  the  pronator  teres  internally,  and  the 
supinator  longus  externally,  and  divides  opposite 
the  coronoid  process  of  the  ulna  into  its  terminal 
branches,  the  Radial  and  Ulnar  arteries. 

RADIAL  ARTERY 

Extends  from  the  elbow  to  the  wrist,  in  a  line  from 
the  middle  of  the  elbow-joint  to  the  root  of  the  thumb. 
Rel.  Ext.  Supinat.  Rad.  Long.;  and  for  some  distance 
the  radial  nerve.  Int.  Pronator  teres,  and  flexor 
carpi  radialis.  Post,  attachments  of  the  supin.  brevis 
and  pron.  teres ;  flexor  long.  poll. ;  and  ant.  surface 
of  the  radius.  Ant.  above  supin.  long.,  below  fascia 
and  skin.  Ram.  1,  Recurrent,  anas,  with  the  sup. 
Profunda;  2,  Superficialis  Volse,  runs  over  the  annu- 
lar lig.  through  the  short  muscles  of  the  thumb  to 
join  and  complete  the  superficial  palmar  arch;  3, 
Ant.  Carpi  Radialis. 

The  vessel  now  passes  backwards  beneath  the  two 
first  extensors  of  the  thumb  to  the  first  interosseous 
space,  which  it  traverses  above,  or  through  the  fibres 
of  the  abductor  indicis  m.  Here  it  may  be  felt  in  a 
space  bounded  by  the  two  first  extensor  tendons  of  the 


ULNAR   ARTERY.  157 

thumb,  and  that  of  the  third,  Ram.  at  this  stage.  4, 
Dorsalis  carpi,  Rad.  carpus  and  wrist-joint;  5,  and  6, 
Dorsalis  Pollicis,  dorsal  edges  of  the  thumb  ;  7,  Pr-in- 
ceps  vel  magna  pollicis,  runs  between  the  abd.  indicis 
and  abd.  pollicis,  divides  at  the  first  phalanx  of  the 
thumb  into  its  two  margin  branches ;  8,  Radialis 
Indicis,  anas,  with  the  superf.  palmar  arch,  and  be- 
come a  digital  artery.  The  terminal  branch,  or  Pal- 
mar is  prof  unda,  crosses  the  carpal  heads  of  the  meta- 
carpal  bones,  covered  by  all  the  soft  parts,  and  on  that 
of  the  little  finger  joins  the  Ram.  communic.  of  the 
ulnar  art.  and  thus  forms  the  deep  palmar  arch.  The 
Ram.  of  this  arch  are  five  in  number.  They  supply 
the  inter ossei,  and  at  the  cleft  of  the  fingers,  join  the 
branches  of  the  superficial  arch  before  they  bifurcate. 

ULNAE,  ARTERY 

Descends,  with  a  curve  towards  the  inner  side  of 
the  arm,  from  the  elbow  to  the  inner  side  of  the  pisi- 
form bone.  Rel.  at  the  upper  third  of  the  arm  it  lies 
between  the  two  layers  of  flexor  muscles ;  it  after- 
wards rests,  with  the  ulnar  nerve  on  its  outside,  on 
the  flexor  profundus.  At  the  middle  third  of  the 
arm  it  is  covered  by  the  adjoining  edges  of  the 
flexor  sublim.,  and  flex,  carpi  ulnaris;  at  the  lower 
third  by  the  skin,  and  fascia :  Ram. 

1 — 2,  art  recurrent,  ant.  et  post,  anas.,  the  first 
with  the  anastomotica  magna  and  the  inf.  protunda ; 
the  second  with  the  former  vessel  and  the  sup.  pro- 
funda;  3,  interossea,  runs  downwards  and  backwards 
to  the  interosseous  space,  where  it  gives  off"  two  recur- 
rent branches,  and  the  ram.  interos.  post. ;  it  then  de- 
scends on  the  ant.  surface  of  the  ligament,  and  at  the 
upper  edge  of  the  pronator  quadratus  divides  into  ant. 
and  post,  carpal  branches,  the  former  anas,  with  the 
deep  palmar  arch,  and  the  latter  with  the  ram.  dorsa- 
lis  carpi.  The  ram.  interos.  post.  perf.  the  upper  part 
of  the  lig.,  gives  off  a  post,  interos.  recurrent,  and 
14 


158  BRONCHIAL    ARTERIES. 

descends  as  far  as  the  dorsum  of  the  carpus.  The 
recurrent  branches  anas,  with  branches  of  the  radial 
art. ;  4,  descend.  muscul.  vel  nervi  mediant  to  the  super- 
ficial flexors ;  5,  6,  r.  carpi  ulnaris,  ant.  and  post. 

The  ulnar  artery  now  passes  from  the  inner  side 
of  the  pisiform  bone,  over  the  annular  lir*.,  gives  off 
the  communicans  profund.  to  complete  the  deep  pal- 
mar arch,  and  then  as  the  r.palmaris  super/,  it  arches 
across  the  hand,  beneath  the  palmar  fascia  and  skin, 
and,  between  the  ball  of  the  thumb  and  index  finger, 
joins  the  superf.  volae  and  rad.  indicis,  to  form  the 
super/,  palmar  arch.  Four  digital  branches  are  given 
off,  each  of  which  first  anas,  with  a  branch  from  the 
deep  arch,  and  then  divides  into  two  collateral 
branches;  they  supply  the  edges  of  the  three  last 
fingers  and  the  ulnar  side  of  the  index. 

The  digital  vessels  and  nerves  run  along  the  late- 
ral surfaces  of  each  finger,  and  nearer  its  anterior 
surface;  they  terminate  in  a  free  anastomosis  in  the 
expanded  extremities  of  the  fingers,  and  endow 
these  with  common  sensibility,  and  the  special  sense 
of  touch. 

THE  THORACIC  AORTA 

is  situated  in  the  post,  mediastinum,'  and  extends 
from  the  left  side  of  the  fourth  dorsal  vertebra  to  the 
aortic  opening  of  the  diaphragm.  Rel.  ant.  the  left 
pleura,  root  of  the  left  lung,  oesophagus,  the  left  au- 
ricle of  the  heart,  and  pericardium,  post,  left  side, 
and  afterwards  the  fore  part  of  the  spinal  column: 
owing  to  this  inclination,  the  oesophagus  and  vagi, 
which  above  are  placed  on  its  right  side,  cross  it  to 
lie,  below,  rather  to  its  left  side;  behind  it,  also,  are 
the  left  intercostal  veins,  going  to  join  the  azygos.  The 
splanchnic  nerves  lie  on  each  side  of  it,  and  the  tho- 
racic duct  and  azygos  vein  on  its  right  side.  Ram. 
Bronchials,  generally  four  in  number,  two  on  each 
side ;  their  branches  twine  around  the  bronchi  to  sup- 
ply the  substance  of  the  lung;  anas,  with  the  pulmo- 


(XELIAC   AXIS.  159 

nary  artery  (Ruysch,  Cowper,  Waller,)  with  the  pul- 
monary veins  (Harrison.) 

(Esophageal,  from  one  to  four  or  five  to  the  oesopha- 
gus; they  anas,  with  other  art.  by  ascending  and  de- 
scending branches. 

Inter  co  stales,  from  eight  to  ten  on  each  side,  they 
run  in  the  eight  or  ten  inf.  intercostal  spaces,  and 
anas,  with  the  int.  mammary  a.  Each  gives  off  a  ram. 
postic.,  which  passes  between  the  spine  and  costo- 
transverse  lig.  to  supply  the  cord,  and  deep  dorsal 
muscles. 

THE  ABDOMINAL  AORTA 

descends,  inclining  slightly  to  the  left  side,  from  the 
diaphragmatic  opening  to  the  body  of  the  fourth  or 
fifth  lumbar  vertebra.  Rel.  ant.  lesser  omentum,  sto- 
mach, solar  plexus,  vena  porta,  mesenteric  vessels, 
pancreas  and  duodenum,  transverse  mesocolon,  root 
of  the  mesentery,  and  small  intestines.  Right  side, 
vena  cava,  thoracic  duct ;  both  these  vessels  are  be- 
hind it  at  their  origins.  On  each  side  lies  the  sym- 
pathetic nerve.  Post,  the  pillar  of  the  diaphragm 
and  lumbar  vertebrae.  Ram. 

Diaphragmatic,  right  and  left,  they  encircle  the  di- 
aphragm, and  join  at  its  ant.  edge;  anas.,  with  lower 
intercost.  arts. 

CCELIAC  AXIS,  a  short  trunk  projecting  horizontally 
from  the  aorta  immediately  below  its  diaphragmatic 
opening.  Rel.  the  pancreas  and  vena  porta  below 
it;  the  lob.  Spigelii  on  its  right;  the  renal  capsules 
and  semilunar  ganglions  on  each  side;  enveloped  by 
the  solar  plexus  and  covered  by  the  stomach.  It  is 
an  axis  of  three  branches. 

a,  Gastric  or  coronar.  ventriculi,  runs  to  the  cardiac 
orifice  of  the  stomach,  and  divides  into,  1,  ram.  super. 
to  the  oesophagus,  and  larger  end  of  the  stomach;  2, 
ram.  infer,  follows  the  lesser  curvature,  anas,  with  the 
sup.  pyloric  art.  of  the  hepatic. 


160        SUPERIOR    MESENTERIC   ARTERY. 

HEPATIC,  runs  enclosed  within  the  smaller  omen- 
turn,  1st,  transversely  towards  the  pylorus,  and  2dly, 
upwards  and  forwards  to  the  transverse  fissure  of  the 
liver.  Ram.  1st  stage,  1,  sup.  pyloric,  to  the  pylorus, 
anas,  infer,  branch  of  the  gastric ;  2,  gastro-duode- 
nalis,  accompanies  the  ductus  communis  choledochus, 
and  between  the  duodenum  and  pancreas,  divides  into 
pancreatico  duodenalis,  and  gastro-ejnploica  dextra. 
The  former  supplies  the  corresponding  organs,  the 
latter  runs  along  the  larger  curvature  of  the  stomach, 
and  anas,  with  the  gastro-epiploica  sinist.,  a  branch 
of  the  splenic. 

Terminal  Branches. 

3,  Hepatica  sinistra,  left  lobe  of  the  liver ;  4,  hepatica 
dextra,  to  the  right  lobe;  from  this  is  derived  the  ram. 
cystica  to  the  gall  bladder. 

SPLENIC,  five  or  six  inches  long;  it  runs  with  the 
vein  to  the  left  side,  along  the  upper  and  post,  part  of 
the  pancreas,  and  terminates  by  five  or  six  br.  in  the 
spleen.  Ham.  1,  pancreatic 'se  parvse,  ramusculi  to  the 
gland ;  2,  pancreatica  magna,  runs  from  left  to  right 
along  with  the  duct;  3,vasabrevia;  five  or  six  large, 
but  short,  branches  arising  from  the  trunk,  or  its 
splenic  divisions,  to  ramify  in  numerous  anas,  on  the 
larger  end  of  the  stomach ;  4,  splenicse,  five  or  six  in 
number,  to  the  spleen;  5,  gastro-epiploica  sinistra, 
runs  from  left  to  right  on  the  larger  curvature  of  the 
stomach  to  anas,  with  the  right  corresponding  ves- 
sels from  the  hepatic. 

SUPERIOR  MESENTERIC,  arises  from  the  aorta  at  the 
lower  edge  of  the  pancreas,  which  separates  it  from 
the  coeliac,  and  above  the  transverse  portion  of  the 
duodenum.  It  descends,  forming  a  slight  curve,  to 
the  right  iliac  fossa.  Ram.  1st,  from  its  convexity. 

a,  Mesentericse,MteQn  or  twenty  branches,  they  anas. 
with  each  other  in  a  series  of  arches,  which  become 
smaller  and  more  numerous  as  they  approach  the 
small  intestines,  to  which  they  are  finally  distributed. 


RENAL   ARTERIES.  161 


2d,  from  its  Concavity. 

b,  Colica  media,  to  the  transverse  colon,  anas,  on 
the  left,  with  the  colica  sinist.,  on  the  right  with  the 
colica  dextra. 

c,  Colica  dextra,  to  the  ascending  colon,  anas,  above 
with  the  colica  media,  below  with  the  ilio  colic. 

d,  Ilio  colic,  to  the  caecum,  valve,  &c.,  anas,  above 
with  the  colica  dextra,  below  with  branches  from 
the  inferior  mesenteric  art. 

INFERIOR  MESENTERIC,  arises  about  an  inch  above 
the  bifurcation  of  the  aorta,  and  descends  towards 
the  left  iliac  fossa.  Ram. 

a,  Colica  sinistra,  to  the  descending  colon,   anas. 
above  with  the  colica  media,  below  with  the  art. 
sigmoidea. 

b,  Art.    sigmoidea,  to    the  sigmoid  flexure,  anas. 
above  with  colica  sinistra,  ram.  to  the  psoas,  iliacus 
m.  and  ureter. 

c,  Hsemorrhoidalis  superior,  descends  in  the  meso- 
rectum  to  the  rectum,  and  at  about  its  middle  divides 
into  two  branches,  which  descend  on  the  sides  of  the 
organ,  some  of  their  ramusculi  even  reaching  the 
anus;  anas,  with  the  middle  and  inf.  hsemorr.  art. 

All  the  foregoing  branches  of  the  abd.  aorta  are 
accompanied  each  by  a  plexus  of  nerves,  named  after 
each  vessel,  and  derived  from  the  semilunar  gang- 
lion, solar  plexus,  and  sympathetic  nerve.  Their 
blood  is  returned  by  the  vena  porta,  which  passes 
through  the  liver  before  pouring  its  blood  into  the 
inf.  vena  cava. 

Copsulares,  large  in  the  foetus,  supply  the  supra- 
renal capsules. 

RENALES,  arise  between  the  two  mesenteric  arte- 
ries, the  right,  which  is  the  longer,  passing  behind 
the  vena  cava.  Their  branches,  four  or  five  in  num- 
ber, run  between  the  mammillae  of  the  kidney,  anas. 
14* 


162  COMMON    ILIAC    ARTERIES. 

in  arches,  and  then  terminate  in  its  cortical  sub- 
stances. Some  branches  reach  the  capsule. 

Spermaticse  arise  immediately  below  the  former, 
the  right  frequently  from  the  right  renal.  They  de- 
scend, crossing  the  psose  m.  and  ureter  on  each  side, 
and  at  the  inner  ring  join  the  vas  deferentia,  which 
guide  them  to  the  testicles.  In  the  female  they  run 
to  the  ovaria. 

Ram.  in  the  male,  a,  ram.  to  the  psose,  ureter,  and 
adjoining  tissue;  b,  six  or  seven  to  the  epididymis 
and  body  of  the  testis. 

In  the  female,  a,  ram.  to  the  ovaries,  especially  to 
the  uterus,  where  they  anas,  with  the  uterine  arte- 
ries; b,  ram.  accompany  the  round  lig. 

Lumbales,  five  in  number,  corresponding  to  the 
vertebral  spaces.  They  divide  into,  a,  ram.  spinales 
to  the  cord,  and  through  anutr.  foramen  to  the  body 
of  each  lumbar  vertebra ;  b,  post,  muscular;  c,  circu- 
lar or  abdominal,  analogous  in  their  course  to  the  in- 
tercostales  with  which  they  anastomose. 

Terminal  Branches  of  the  Aorta. 

Sacra  media  (caudal  artery  of  animals)  descends 
on  the  sacrum  and  coccyx ;  it  supplies  the  rectum, 
and  anas,  at  each  division  of  the  above  bones  with 
the  lateral,  sacral,  and  hsemorrhoidal  arteries. 

The  abd.  aorta  at  its  bifurcation  lies  in  front  of, 
and  a  little  to  the  left  side  of,  the  fourth  lumbar  ver- 
tebra ;  it  is  here  nearly  opposite  the  umbilicus,  and 
has  the  vena  cava  to  its  right  side,  the  sympathetic 
on  either  side ;  it  bifurcates  into  the 

ILIACJB  COMMUNES 

extend  from  the  fourth  lumbar  vertebra  to  the  sacro 
iliac  artic.  Rel.  crossed  by  the  ureters  and  spermatic 
vessels,  resting  above  upon  the^bodyof  the  last  lumbar 
vertebra,  below  against  the  inner  edge  of  the  psoasm. 
The  two  corresponding  veins  lie  beneath  and  on  their 


OBTURATOR   ARTERY.  163 

inner  sides,  and  the  left  in  j  oining  the  right  to  form  the 
vena  cava  ascend. ,  passes  beneath  the  right  iliac  artery. 
Ram.  to  the  psooe,  ureters,  &c.,  they  sometimes 
give  off  the  sacra  media,  and  last  lumbar  arteries, 
and  even  therenales,  and  spermaticse  (Cruveilhier;) 
b,  ram.  terminal,  iliacse  extern  et  intern. 

INTERNAL  ILIAC, 

About  an  inch  and  a  half  long,  descends  vertically 
(bending  slightly  forwards)  from  the  sacro  iliac  joint 
to  the  upper  edge  of  the  sacro  sciatic  notch.  Many 
of  its  branches  sometimes  arise  from  a  common  trunk. 

Anterior  Set  of  Branches. 

a.  Umbilical,  large  in  foetal  life,  they  soon  dwin- 
dle after  birth   into  fibrous   cords,  which  may  be 
traced  along  the  sides  of  the  bladder  to  the  umbili- 
cus ;  near  their  origins,  where  they  still  remain  per- 
vious, some  of  the  principal  vesical  branches  arise. 

b.  Vesicates,  four  or  five,  derived  principally  from 
the  umbilical,  and  from  the  middle  hsemorr.  obtur- 
ator, vaginal,  and  uterine  arteries.     Earn.,  1,  infer. 
vesic.  semin.,  prostate  gland,  and  neck  of  the  bladder; 
2,  media,  along  the  uterus  to  the  sides  of  the  blad- 
der; 3,  super.,  ant.  surface  of  the  bladder. 

c.  Obturator,  may  arise  from  the  femoral  or  epi- 
gastric art.,  when  it  winds  round  the  infer.,  or  the 
super,  and  inner  margins,  of  the  femoral  ring.  It 
runs  parallel  to,  but  below,  the  ext.   iliac   vessels, 
accompanied  by  its  nerve  (which  is  above  it,)  to  the 
obturator  foramen.  Ram.  1,  a  cross  branch,  by  which 
it  joins  its  fellow  behind  the  pubis;  2,  vesicalesmuscu- 
lares,  iliacseto  anas,  with  the  circumflexa  ilia.   Having 
traversed  the  obturator  foramen,  its  branches  are, 
1,  Ram.  intern,  runs  round  the  inner  half  of  the  ob- 
turator foramen,  between  the  two  obt.  m.,  which  it 
supplies,  and  anas,  with  the  ram.   extern.  ;  a  branch 
descends  between  the  two  first  adductor  m.    2,  ram 


164  ISCHIATIC   ARTERY. 

extern,  between  the  obt.  m.  round  the  ext.  half  of 
the  foramen,  anas,  between  the  neck  of  the  femur 
and  quadratus  muscle  with  the  ischiatic  art. ;  a 
branch  enters  the  joint  through  the  notch;  other  br. 
supply  the  muscles. 

Int.  Branches. 

d.  Middle  hsemorrhoidal,  to  the  ant.   part  of  the 
rectum,    anas.,   above    and   below,    with   the  other 
haemorrh.  branches. 

e.  Uterine,  runs  in  the   broad  lig.  to  the  neck  of 
the  uterus,  on   wThich  it  ascends  to  anas,  with   the 
spermatic  art. 

f.  Vaginales,  surround  the  vagina. 

Posterior  Branches. 

g.  Heo-lumbar,  divides  behind  thepsoas.  m.  into, 
I,  ram.  ascend.,  anas,  with  the  last  lumbar   art.;  2, 
transversales,  superficial  and  deep,  to   the  iliacus  m.; 
8,  the  nutritious  art. 

h.  Sacra  lateralis,  descends  in  front  of  the  sacral 
foramina.  Ram.  to  the  spinal  cord,  and  to  the  mus- 
cles on  the  back  of  the  sacrum;  anas,  with  the  sacra 
media.  

i.  GLUTEAL,  escapes  between  the  upper  edge  of 
the  sciatic  notch  and  pyriformism.,  and  immediately 
divides  into,  1,  ram.  super/.,  runs  between  the  g. 
max.  et  medius  m. ;  2,  r.  profund.,  between  the  g. 
medius  and  minim. ;  it  sends  a  branch  along  the  g. 
min.  to  the  spin.  p.  of  the  ilium,  a  second  across  this 
m.  to  the  g.  medius,  a  third  through  the  g.  min.  to 
the  artic.  capsule. 

Inf.  Branches. 

k.  ISCHIATIC,  escapes  from  the  pelvis,  between 
the  lower  edge  of  the  pyrif.  and  sciatic  lig.  Ram.  to 
the  gluteus  max.,  lev.  ani,  and  coccygeus  m. ;  2, 
comes  nervi  ischiatici. 


CAVERNOUS   ARTERIES.  165 

1.  INTERN.  PUDIC,  descends  upon  the  pyriforrnis 
m.,  internal  to  the  former  vessel,  with  which  it 
escapes  from  the  pelvis ;  2,  it  winds  over  the  spine  of 
the  ischium,  beneath  the  larger  sciat.  lig.,  and  enters 
the  smaller  sciatic  notch;  3,  it  ascends  on  the  inner 
side  of  the  tuber  ischii  and  rami  ischii  et  rubis,  but 
not  within  the  pelvis,  to  the  arch  of  the  pubes,  cov- 
ered and  protected  by  a  prolongation  of  the  large 
sacr.  sciatic  lig.,  as  far  as  the  crus  penis. 

Ram. — First  Stage. 

1.  Vesical,  prostatic,    and   sometimes   the    middle 
hsemorrhoidal. 

Second  Stage. 

2.  Anastomotic,  anas,  with  the  ischiatic  and  int. 
circumflex  art. ;  3,  musculares,  to   the  flexors  at  the 
tuber  ischii. 

Third  Stage. 

4.  Ext.  hsemorrhoidales,  two  or  three  to  the  anus ; 
5,  perineal  (superf.)  pierces  the  middle  fascia  of  th  e 
permseum  to  get  into  the  space  between  the  accel. 
urinse  and  erect,  penis  m. ;  it  ascends  to  the  septum 
scroti,  which,  and  the  superficial  parts  of  the  peri- 
neum, it  supplies;  6,  transvers.  perinea  (superf.)  to 
the  perinaeum  and  anus;  7,  corp.  bulbosi  (deep  trans- 
verse perinosal,)  runs  inwards  behind  the  middle  pe- 
rinseal  fascia,  to  the  bulb,  Cowper's  glands,  &c. 

Terminal  Branches. 

8.  Corp.  cavern,  to  those  bodies ;  9,  dorsalis  penis 
the  two  latter  anas,  by  a  cross  branch,  or  unite  into 
a  single  vessel;  then  pierce  the  suspensory  ligament, 
and  run  on  the  dorsum  of  the  penis  as  far  as  the 
glans. 

The  internal  iliac  art.  is  accompanied  by  its  vein, 
which  lies  anterior  and  internal  to  it ;  behind  it  is  the 


166  FEMORAL   ARTERY. 

sacral  plexus,  with  whose  branches  those  of  the  art. 
interlace,  and  still  more  posteriorly  the  origins  of 
the  pyriformis  muse. 

EXTEKNAL  ILIAC 

extends  from  the  sacro  iliac  joint,  to  the  inf.  edge  of 
Poupart's  lig.,  in  a  line  leading  from  a  point  half  an 
inch  external  to  its  middle,  to  the  umbilicus.  Rel. 
bound  down  by  a  process  of  the  iliac  fascia ;  it  lies, 
first,  to  the  inner  side,  and  then  on  the  fore  part  of, 
the  psoas  muscle,  to  which  it  is  connected  by  a  layer 
of  the  iliac  fascia;  the  vein  lies  on  its  inner  side; 
close  to  Poupart's  ligament  it  is  crossed  by  the  ilio 
scrotal  nerve.  It  is  surrounded  by  numerous  lym- 
phatics, and  covered  by  their  glands.  Ram. 

a.  Epigastric,  Or.  from  any  point  of  the  inferior 
inch  and  a  half  of  the  artery.     It  first  reaches  the 
inner  margin  of  the  int.  inguinal  ring,  and  then  as- 
cends inwards  between  the  peritoneum  and  fascia 
transversalis  ;  it  soon  enters  the  sheath  of  the  rectus 
m.,  in  which  it  term,  about  an  inch  on  the  outer  side 
of  the  umbilicus.     Rel.,  the  spermatic  cord  lies  in 
front,  the  vas  deferens  looking  round  it  to  descend 
to   the   vesic.   semin.     Ram.,  1,    cremasteric  to    that 
structure  and  the  scrotum ;  to  the  round  lig.  in  the 
female ;  2,  anastomotic,  anas,  with  its  fellow  and  the 
obturator  art. ;  3,  terminal  anas,  in  the  rectus,  with 
the  int.  mammary  art. 

b.  Circumflexa  ilii  (internal,)  outwards,  along  Pou- 
part's lig.  and  crista  ilii ;  anas,  with  the  last  lumbar, 
and  the  ilio  lumbar  art. 

FEMORAL  ARTERY 

extends  from  the  termination  of  the  ext.  iliac  to  the 
lower  third  of  the  thigh,  in  a  line  leading  from  the 
middle  of  Poupart's  lig.  to  the  inner  side  of  the  inter- 
nal condyle  of  the  femur.  Rel.  at  the  upper  third  of 
the  thigh  it  lies  in  a  triangle  (Scarpa's)  formed  by 


PROFUNDA.   ARTERY.  167 

Poupart's  lig.,  the  sartorius,  and  add.  longus,  covered 
only  by  skin,  fascia,  and  glands ;  at  the  middle  third 
it  is  covered  by  the  sartorius.  It  rests  on  the  tendon 
of  the  psoas  and  iliacus  m.,pectineus,  and  adductor 
longus  m.  The  vein  and  artery  are  enclosed  in  a 
sheath  from  the  fascia  lat.  This  sheath  becomes  a 
strong  fib.  canal,  where  the  vessels  rest  on  the  tendon 
of  the  adductor  longus,  beneath  the  sartorius  muscle. 
The  vein,  at  first  on  its  inner  side,  gets  more  and 
more  behind  it  as  it  descends ;  the  ant.  crural  nerve 
sends  its  saphenous  branch  into  the  upper  part  of  its 
sheath :  the  vena  saphena  runs  between  the  skin  and 
fascia,  a  little  to  its  inner  side.  Ram. 

a,  Superficial  epigastric  and  superficial  circumflexa 
ilii,  to  the  abdominal  integuments;  b.  super/,  pudic, 
two  or  three  running  beneath  the  fascia  to  the  scro- 
tum; c,  muscular  super/.,  to  the  iliacus,  psoas,  and 
rectus  m. 

d.  PROFUNDA,  Or.  generally  an  inch  or  an  inch  and 
a  half  below  Poupart's  ligament.  It  is  placed  behind, 
and  separated  from  the  femoral  by  the  pro/un.  and 
/em.  veins,  and  ad.  long.  Ram.  1,  ext.  circumflex, 
passes  between  the  sartorius  and  rectus  m.,  divides 
into  a  transv.  branch  to  the  hip-joint  and  muscles,  and 
a  ram.  descend.,  which  runs  between  the  rectus  and 
crureus,  as  far  as  the  knee;  2,  intern,  circumflex., 
passes  backwards,  between  the  pectineus  andr  psoas 
m.;  ram.  superior  to  the  digital  fossa;  ram.  transv. 
between  the  quad.  fern,  and  add.  long,  to  flexor  m. 
8,  perf or  antes,  three  in  number — 1,  super.,  backwards 
between  the  add.  brevis  and  pectineus;  2,  media. 
through  the  add.  brevis  and  magnus;  3,  infer., 
through  the  add.  magnus,  at  the  upper  edge  of  the 
add,  longus;  4,  r.  terminal,  passes  behind  the  add. 
longus,  and  perforates  the  add.  mag.  These  vessels 
supply  the  flexor  muscles  on  the  back  of  the  thigh, 
and  form  a  chain  of  anastomoses  by  their  ascending 
and  descending  branches;  5,  anastomotica  magna. 


168  ANTERIOR   TIBIAL   ARTERY. 

Sometimes  a  large  artery ;  descends  towards  the  inner 
condyle,  and  there  enters  into  numerous  anastomoses. 

POPLITEAL  ARTERY 

extends  from  the  femoral  opening  in  the  add.  mag- 
nus  to  the  inf.  edge  of  the  popliteus  m.,  in  a  line 
descending  along  the  centre  of  the  back  part  of 
the  knee-joint.  It  rests  in  a  mass  of  fatty  tissue  in  a 
diamond-shaped  space,  formed  above  by  the  diver- 
gence of  the  ham-string  m.,  and  below  by  the  conver- 
gence of  the  two  heads  of  the  gastrocnemius.  The 
vein  is  posterior  and  external  to  the  art.,  and  the 
popliteal  nerve  is  in  similar  relation  with  the  vein. 
Ram. 

a.  Muscular  super.,  two  or  three  to  the  ham-string 
mus. 

b.  Artie,  super,  ext.,  winds  around  the  femur,  be- 
neath the  biceps  tendon,  and  divides  into  r.  super/., 
which  ramifies  on  the  patella  and  r.  profund.  to  the 
synovial  membrane  and  femur. 

c.  Artie,  super,  int.  winds  round  the  inner  side  of 
the  femur,  beneath  the  inner  ham-strings. 

d.  Artie,  inf.  ext.,  runs  along  the  edge  of  the  ext. 
semilunar  cart. 

e.  Artie.- inf.  ext.,  winds  around  the  inner  side  of  the 
tibia.     These  three  art.,  like  the  first,  divide  into 
superf.  and  deep  branches,  which  anas,  the  former 
on  the  patella,  the  latter  about  the  joint. 

f.  Artie,  media  (Azyga,)  perforates  the  lig.  postic. 
to  supply  the  joint. 

g.  Muscular  infer.,  (Surales,)  to  the  gastrocnemius. 
The  popliteal  art.  now  termin.  into  the  Ant.  and  Post, 
tibial  art. 

ART.  TIBIALIS  ANTIC.,  runs  between  the  heads  of 
the  tibialis  post,  m.,  and  above  the  upper  edge  of  the 
interosseous  ligament;  descends  on  its  ant.  surface, 
and  terminates  in  the  fissure  between  the  tarsal  heads 
of  the  first  and  second  metatarsal  bones.  Eel.  between 


EXTERNAL  PLANTAR  ARTERY.     169 

the  exten.  comm.  and  tibialis  antic,  m.  above,  be- 
tween the  former  and  exten.  prop.  pol.  below.  The 
nerve  runs  on  its  outer  side.  Ram. 

a.  Recurrent,  anas,  with  the  int.  artic.  a. 

b.  Musculares,  adjacent  muscles. 

c.  Internal  malleolar,  and  d.  ext.  malleolar,  ramify 
on  those  processes. 

f.  Metatarsal,  which  gives  three  dorsal  interosseous 
branches. 

g.  Pollicis,  supplies  the  two  sides  of  the  first  toe, 
and  inner  side  of  the  second. 

h.  Communicans  (terminal,)  joins  the  ext.  plantar 
artery  in  the  sole  of  the  foot,  to  complete  the  plantar 
arch. 

POST  TIBIAL  ABT.  descends  between  the  superficial 
and  deep  flexor  muscles  to  a  point  midway  between 
the  int.  malleolus  and  os  calcis;  in  its  course,  it 
rests  successively  on  the  tibialis  posticus,  flexor 
communis,  and,  lastly,  on  the  bone,  where  it  is  placed 
between  the  sheath  which  encloses  the  tendons  of 
the  two  last  named  muscles,  and  that  of  the  flexor 
prop,  pollicis.  Ram. 

a.  Peroneal,  descends  between  the  inner   edge  of 
the  fibula  and  attach,  of  the  flexor  pollicis  m.  to  the 
ext.  malleolus.     Ram,.  1,  ant.  peroneal,  pierces  the 
interosseous  ligament  to  reach  the  tarsus  ;  2,  terminal, 
to  the  outer  malleolus,  &c. 

b.  Internal  plantar  art.  runs  upon  the  upper  sur- 
face of  the  adductor  pollicis  m.  to  the  integuments  of 
the  great  toe;  sometimes  it  joins  a  branch  from  the 
next  vessel,  to  form  a  superficial  plantar  arch. 

c.  Ext.  plantar  art.  runs  first  to  the  tarsal  end  of 
the  fifth  metatarsal  bone,  and  then  across  the  foot 
next  the  interosseous  muscles,  to  join  the  communicans 
of  the  ant.  tibial,  and  form  the  principal  palmar  arch. 
Ram.  I,  per  for  antes,  three  in  number;  they  pierce  the 
interossei  to  join  the  interosseous  branches  of  the  me- 
tatarsal artery ;  2,  digital,  four  in  number,  arise  from 

15 


170  COLLATERAL   CIRCULATION. 

the  convexity  of  the  arch,  and  supply  both  sides  of 
the  three  last  toes,  and  outer  side  of  the  second. 

Collateral  Circulation. 

The  most  remarkable  feature  in  the  arrangement 
of  the  blood-vessels  is  their  anastomoses.  The  arte- 
ries and  their  branches  enter  into  combinations 
with  each  other  at  every  possible  opportunity. 

A.  Every  artery  anastomoses  with  its  fellow,  ex- 
cepting some  supplying  the  viscera,  and  those  in  the 
extremities. 

B.  Every  artery  anastomoses  with  the  vessel  im- 
mediately above  and  below  it. 

C.  Every  artery  anastomoses  with  itself  by  means 
of  its  branches,  which  follow   the  general  rules  of 
anastomoses. 

As  interesting  examples  of  the  first  may  be  men- 
tioned : — The  anas,  between  the  ant.  cerebral  art.  of 
the  int.  carotids  by  the  ant.  communicans. 

2.  Between  the  obturator  arteries,   before  their 
exit  from  the  pelvis,  by  a  transverse  branch. 

3.  Between  the  dorsal  arteries  of  the  penis,  by  a 
transverse  branch. 

4.  Between  the  vertebral  arteries,  which  unite  to 
form  a  single  vessel,  the  basilar. 

5.  Between  the  epigastric  art.,  by  a  transverse 
branch. 

6.  Between  the  ext.  carotids,  by  nearly  every  one 
of  their  branches,  which  also  form  the  most  remark- 
able examples  of  the  second  rule,  &c.,  &c. 

7.  The  intercostals  and  upper  lumbar  arteries  en- 
circle the  trunk. 

Examples  of  the  second  rule. 

1.  In  the  inf.  extremity,  all  the  branches  of  the 
ext.  iliac  and  femoral  arteries  form  a  posterior  or 
principal,  and  anterior  or  minor  collateral  circula- 
tion, by  a  chain  of  anastomoses  along  the  limb,  each 


COLLATERAL  CIRCULATION.      171 

of  which  is   sufficient  to  carry  on  the  circulation 
when  the  principal  trunk  is  obliterated. 

2.  In  the  superior  extremity,  a  chain  of  anas,  may 
be  traced  along  the  margins  of  the  scapula,  inner 
edge  of  the  arm,  &c. 

3 .  From  the  angle  of  the  eye,  along  the  nose,  mouth, 
face,  and  median  line  of  the  neck ;  and,  by  means 
of  the  int.  mammary  and  epigastric  arteries,  along 
the  chest  and  abdomen,  even  to  the  principal  art.  of 
the  inf.  extremities. 

4.  Along  the  oesophagus,  stomach,  and  intestines, 
an  anastomotic  chain  may  be  traced  from  the  pharynx 
to  the  rectum. 

5.  Along  the  spinal  cord,  by  means  of  the  spinal 
arteries  which  hold  numerous  anastomoses  through 
the  intervcrtebral  formina  with  the  vertebral,  inter- 
costal, lumbar,  and  sacral  arteries. 

As  interesting  examples  of  the  third  rule  may  be 
mentioned, 

1.  The  branches  of  the  external  and  internal  caro- 
tids; the  former  in  the  brain,  the  latter  in  the  neck. 

2.  The  branches  of  the  coeliac  axis,    round   the 
stomach;    the  coronary  arteries,  round  the  heart; 
the  ciliary  arteries  round  the  iris,  between  its  larger 
and  smaller  circles;  the  branches  of  the  super,  and 
inferior  mesenteric  arteries,   especially  the  former: 
the  branches  of  the  articular    arteries,   especially 
those  of  the  knee-joint.     The  digital   branches  in 
the  hand  and  foot,  the  branches  of  the  obturator  ar- 
tery round  the  margin  of  the  obturator  foramen,  the 
branches  of  arteries  supplying  sphincters,  viz.,  the 
mouth,  anus,  &c. 

A  principle  of  compensation  also  prevails  through- 
out the  arterial  system,  by  which  a  less  than  ordi- 
nary supply  from  one  vessel  is  balanced  by  a  more 
than  ordinary  supply  from  another. 


172  THE    VEINS. 


SECTION  III. 
OF  THE  VENOUS  SYSTEM. 

As  the  arteries  distribute  the  blood  from  the  heart 
to  the  different  parts  of  the  body,  so  the  veins  return 
it  back  again  to  the  heartland  thus  the  general  cir- 
culation is  carried  on. 

As  the  veins  have  been  generally  described  with 
the  arteries,  it  will  not  be  necessary  again  to  enter 
upon  their  description;  the  following  will  be  sufficient. 

The  blood  from  the  brain  is  returned  by  the  int. 
jugular ;  this  is  formed  by  the  conflux  of  the  sinuses 
at  the  foramen  lacerum  posterius,  passes  out  through 
this  with  the  eighth  pair  of  nerves,  descends  in  the 
neck,  lying  posterior  and  internal  to  the  int.  carotid 
art.,  and  thence  enters  the  carotid  sheath,  where  it 
lies  to  the  outer  side  of  the  par  vagum  and  ext.  ca- 
rotid, and  in  front  of  the  first  stage  of  the  subcla- 
vian  art.,  joins  the  subclavian  vein  to  form  the 
right  vena  innominata. 

The  blood  from  the  external  parts  of  the  face  is 
returned  by  the  labial  vein,  which  crosses  the  lower 
jaw  posterior  to  the  labial  art.,  descends  in  the  neck 
and  joins  the  int.  jug.,  generally  sending  a  branch  to 
join  the  ext.  jug.;  this  vein  returns  the  blood  from 
the  temporal  and  int.  maxillary  arteries,  descends 
in  the  substance  of  the  parotid  gland,  becomes  su- 
perficial, crosses  the  ext.  surface  of  the  sterno-mas- 
toid,  and  at  its  outer  margin  joins  the  subclavian  vein. 

The  blood  from  the  upper  extremity  is  returned  by 
the  cephalic,  mediam,  and  basilic  veins;  the  two  latter 
join  the  brachial  venae  comites  to  form  the  brachial 
vein  at  or  a  little  above  the  elbow-joint;  the  cephalic 
runs  upwards  along  the  outer  edge  of  the  biceps  nerve, 
then  between  this  and  the  inner  edge  of  the  deltoid 
and  the  pectoralis  major,  and  joins  the  axiliary  vein  a 
little  below  the  clavicle ;  the  axiliary  vein  conducts  the 


POPLITEAL   VEIN.  173 

blood  into  the  subclavian,  which  unites  with  the 
int.  jug.  to  form  the  vena  innominata. 

The  right  vena  innom.  descends  almost  perpendicu- 
larly into  the  thorax,  and  after  a  course  of  about  an 
inch  and  an  half  joins  the  left  to  form  the  vena  cava 
superior.  The  left  vena  innominata  passes  obli- 
quely downwards  and  inwards,  crosses  the  upper 
edge  of  the  arch  of  the  aorta  and  the  vessels  arising 
from  it,  and  on  the  right  side  joins  the  right  vena 
innom.  The  vena  cava  superior  receives  the  vena 
azygos,  perforates  the  pericardium,  and  empties 
itself  into  the  right  auricle  of  the  heart. 

The  blood  from  the  lower  extremities  is  returned 
from  the  foot  and  leg  by  the  venae  comites  accom- 
panying the  arteries,  which  unite  to  form  the  pop- 
liteal vein.  The  blood  from  the  superficial  parts  is 
returned  by  the  int.  and  ext.  saphenoe  veins;  the  int. 
saphena  is  the  larger,  it  arises  about  the  inner  ankle, 
ascends  in  the  superficial  fascia  along  the  inner  side 
of  the  leg  immediately  behind  the  inner  edge  of  the 
tibia,  crosses  along  the  inner  surface  of  the  knee- 
joint,  ascends  along  the  front  of  the  thigh,  and  a  short 
distance  below  Poupart'slig.  perforates  the  cribiform 
fascia,  and  joins  the  femoral  vein;  it  is  accompanied 
in  the  leg  by  the  int.  saphenous  nerve. 

The  ext.  saphena  vein  arises  about  the  outer 
ankle,  ascends  along  the  back  part  of  the  leg  beneath 
the  fascia,  and  joins  the  popliteal  vein;  it  is  accom- 
panied by  the  ext.  saphenous  nerve. 

The  popliteal  vein  terminates  in  the  femoral, 
which  ascends  with  the  femoral  art.  and  terminates 
in  the  ext.  iliac  vein  ;  this  joins  the  int.  iliac  to  form 
the  common  iliac  vein  on  each  side;  the  left  common 
iliac  vein,  longer  than  the  right,  passes  obliquely  to 
the  right  side,  and  unites  with  the  right  behind  the 
iliac  art.  and  aorta  to  form  the  vena  cava  inferior; 
the  right  com.  iliac  vein  passes  upwards,  behind  its 
art.,  to  form  the  vena  cava  inferior. 


174  THORACIC   DUCT. 

The  vena  cava  inferior  ascends  in  front  of  the  lum- 
bar vertebrae,  to  the  right  side  of  the  aorta,  passes 
obliquely  outwards  to  the  right  side,  sinks  into  a 
deep  sulcus  or  canal  in  the  liver,  perforates  the  dia- 
phragm, receiving  here  the  venae  cavse  hepaticae,  and 
almost  immediately  perforates  the  pericardium,  and 
empties  itself  into  the  right  auricle  of  the  heart. 

The  vena  porta  returns  the  blood  from  the  organs 
of  digestion,  or  chylopoietic  viscera,  passes  across 
the  spine  behind  the  pancreas,  being  here  formed  by 
the  junction  of  the  splenic  and  superior  mesenteric 
trunks,  enters  the  transverse  fissure,  and  divides 
into  two  branches  to  ramify  in  the  right  and  left  lobes 
of  the  liver;  its  blood  is  returned  by  the  venae  cavse 
hepaticae.  The  renal  veins  terminate  in  the  inf. 
vena  cava;  the  lumbar  veins  in  the  vena  azygos. 

The  larger  arteries  are  accompanied  by  one  vein, 
the  smaller  by  two,  one  on  each  side,  the  vena  comites . 

The  pulmonary  arteries  carry  black  blood,  the 
pulmonary  veins  red  or  arterial  blood.  In  the  foe- 
tus the  umbilical  vein  carries  red  or  pure  blood,  the 
renal*  arteries  black  or  impure  blood. 

SECTION  IV. 

The  Lymphatic  System. 

The  Lymphatics  are  divided  into  the  lymphatics 
properly  so  called,  and  the  lacteals.  The  lympha- 
tics proceed  from  the  lower  extremities,  accompany- 
ing the  superficial  and  deep  veins,  pass  through  the 
lymphatic  glands  and  join  the  pelvic  lymphatics, 
and  then  unite  in  front  of  the  second  or  third  lum- 
bar vertebra,  behind  the  aorta  and  vena  cava,  to  form 
the  thoracic  duct.  The  lacteals  arise  from  the  small 
intestines,  pass  through  the  mesenteric  glands,  and 
join  the  preceding  to  form  the  thoracic  duct. 

The  Thoracic  duct,  the  trunk  of  the  lymphatic  sys- 
tem, passes  upwards  through  the  aortic  opening  of 
*See  Errata. 


RIGHT    THORACIC    DUCT.  175 

the  diaphragm,  between  the  aorta  on  its  left  and  the 
vena  azygos  on  its  right,  and  enters  the  post,  medi- 
astinum to  terminate  in  the  left  subclavian  vein,  as 
described  with  the  post,  mediastinum. 

The  lymphatics  of  the  right  side  of  the  heart  and 
neck,  and  right  upper  extremity,  unite  to  form  the 
right  thoracic  duct,  which  terminates  in  the  right 
subclavian  vein. 


176 

CHAPTER  VIII. 

NERVOUS  SYSTEM. 

The  Nervous  System  consists  of  the  brain  and  spi- 
nal cord  (cerebro-spinal  axis,)  cerebral  and  spinal 
nerves,  and  the  sympathetic  or  ganglionic  system. 

The  brain  and  spinal  cord  are  lodged  in  the  cranium 
and  vertebral  canal,  which  are  lined  by  a  fibrous  mem- 
brane (dura  mater,)  and  a  serous  membrane  (arach- 
noid, )  for  their  reception.  They  are  further  covered 
by  an  immediate  vesting  membrane  (the  pia  mater.) 

The  Spinal  Cord. 

When  the  spinal  canal,  and  the  above-mentioned 
coverings  are  laid  open,  the  cord  and  the  roots  of  the 
spinal  nerve  are  seen  covered  by  a  shining  investment 
(neurilema.)  The  cord  extends  from  the  pons  Varo- 
lii  to  the  second  or  third  lumbar  vertebra,  where  it 
expands,  and  then  terminates  in  a  lash  of  filaments 
forming  the  cauda  equina.  The  spinal  portion  com- 
mences at  the  foramen  magnum, the  portion  above  that 
point  being  called  medulla  oblong  ata.  The  spinal 
portion  does  not  occupy  the  whole  of  the  canal  formed 
for  it  by  the  vertebrae  and  dura  mater,  a  considerable 
interval  filled  with  fluid  existing  between  them ;  it  is, 
however,  in  some  degree  fixed,  and  its  direction  made 
to  correspond  to  the  curvatures  of  the  spinal  column, 
by  means  of  the  lig.denticulatum.  This  lig.  is  an  ex- 
ceedingly thin  fold  of  the  arachnoid  membrane  en- 
closing a  few  fibres,  and  extending  the  whole  length  of 
the  cord ;  its  inner  edge  is  firmly  attached  to  the  neuri- 
lema, between  the  ant.  and  post,  roots  of  the  spinal 
nerves;  its  outer  edge  is  serrated,  the  teeth  being  at- 
tached to  the  dura  mater,  in  the  intervals  between  the 
sheaths  which  it  furnishes  to  the  several  pairs  of 
nerves  at  their  exit  through  the  intervertebral  fora- 


ANTERIOR    MEDIAN    FISSURE.  177 

mina.  The  first  tooth  separates  the  vertebral  artery 
from  the  hypoglossal  nerve,  and  is  attached  to  the 
occipital  foramen  :  the  last,  which  is  the  twentieth  or 
twenty -first,  is  attached  to  the  vert,  opposite  to  the 
termination  of  the  cord.  The  cord  is  not  of  the  same 
size  throughout,  but  presents  three  remarkable  swell- 
ings, which  corresponds  to  the  great  nervous  plexuses. 
The  first,  medulla  oblongata,  is  in  the  cranium ;  the 
second  extends  from  the  third  cervical  to  the  fourth 
dorsal  vert. ;  and  the  third  commences  at  the  first 
lumbar  vert.,  or  a  little  higher  up,  and  forms  the 
termination  of  the  cord.  The  nerves  of  the  tongue, 
of  respiration,  and  most  of  those  of  the  face,  arise 
from  the  first;  the  nerves  of  the  super,  extremity 
from  the  second ;  and  those  belonging  to  the  infer. 
extremity  from  the  third. 

The  cord  and  nerves  are  closely  invested  by  a  dense, 
fibrous,  but  vascular,  neurilema,  analagous  in  situa- 
tion to  the  pia  mater,  but  much  thicker  and  stronger; 
it  sends  processes  from  its  inner  surface  to  surround 
the  constituent  fibrils,  and  its  outer  surface  is  co- 
vered by  a  mesh  of  vessels,  which  reach  the  cord 
through  numerous  foramina,  between  .the  fibrous  fila- 
ments of  which  it  is  composed.  The  membrane  is 
thrown  into  numerous  zigzag  folds,  in  order  to  allow 
of  temporary  extension  produced  by  the  various  mo- 
tions of  the  body ;  above,  it  is  gradually  lost  in  the  pia 
mater;  below,  it  terminates  in  a  thin,  but  resisting, 
fibrous  cord,  which  is  attached  to  the  dura  mater  lining 
the  sacrum  and  coccyx ;  this  cord,  formerly  considered 
,  a  nerve,  serves  to  fix  the  lower  portion  of  the  spinal 
marrow.  The  exact  figure  of  the  spinal  cord  is  better 
seen  when  deprived  of  its  neurilema.  It  is  composed 
of  two  symmetrical  lateral  portions,  which  are  sepa- 
rated before  and  behind  by  two  fissures. 

The  ant.  median  fissure  penetrates  the  third  of  the 
thickness  of  a  cord  :  its  floor  is  formed  by  the  com- 
missure of  the  cord — a  simple  band  of  homogeneous 


178  LATERAL   TRACTS. 

white  matter,  perforated  by  a  vast  number  of  minute 
vessels,  extending  from  one  half  of  the  cord  to  the 
other.  The  post,  median  fissure  is  much  narrower, 
and  rendered  almost  indistinct  by  the  neurilema ;  nor 
is  it  so  deep  as  the  former,  excepting  at  the  upper  part 
of  the  cord ;  instead  of  a  layer  of  white,  a  thin  layer 
of  cineritious  matter  is  seen  at  the  bottom  of  this 
fissure.  On  the  side  of  the  cord  immediately  external 
to  the  posterior  roots  of  the  spinal  nerves,  a  line  of 
gray  matter  exists,  which  by  cautious  examination, 
will  be  found  to  pass  down  to  the  central  cineritious 
layer  above  mentioned.  This  post,  lateral  cineritious 
line  subdivides  the  cord  into  an  antero-lateral,  and  a 
post,  tract.  Immediately  external  to  the  ant.  roots  of 
the  spinal  nerves  a  faint  line  may  also  be  traced;  but 
here  the  substance  of  the  cord  must  be  broken,  to  ar- 
rive at  the  antero  and  lateral  cinerit.  line,  which  also 
reaches  the  central  layer.  If  this  be  considered  an 
established  line  of  demarkation,  we  shall  have  each  an- 
tero lateral  tract  anatomically  subdivided  into  an  ant. 
tract  and  a  lateral  tract,  according  to  Bell  and  Bel- 
linghcri;  the  latter  being  included  between  the  ant. 
and  post,  roots  of  the  spinal  nerves.  The  disposition 
of  the  cineritious  matter,  which  is  not  the  same  in 'all 
parts  of  the  cord,  is  seen  by  a  transverse  section.  Its 
fundamental  figure  is  sufficiently  well  represented  by 
two  crescents  united  by  a  transverse  line  ) — (.  The 
transverse  line  is  the  layer  at  the  bottom  of  the  post, 
fissure,  and  the  horns  correspond  to  the  ant.  and 
post,  lateral  cineritious  lines. 

Each  half  of  the  cord  appears  to  be  a  riband-shaped 
layer  of  medullary  matter,  curved  round  the  cineri- 
tious substance.  This  medullary  riband  is  separable 
into  two  portions,  the  antero-lateral  and  post,  tracts, 
which  may  be  further  divided  into  a  series  of  wedge- 
shaped  bundles  of  medullary  fibres,  which  extends  the 
,,hole  length  of  the  cord.  The  bases  of  the  wedges 
are  turned  outwards  and  the  apices  inwards ;  they  are 


ANTERIOR   PYRAMIDS.  179 

united  by  their  sides,  and  so  give  the  medullary 
riband,  which  they  form,  the  proper  incurvation. 
The  apices  of  these  wedges  are  not  ranged  in  a  uni- 
form curved  line;  the  consequence  of  this  irregu- 
larity is  a  denticulated  appearance  of  the  outer  sur- 
face of  the  cineritious  layer. 

Medulla  Oblongata,  or  Bulb. 

The  medulla  oblongata  is  that  portion  of  the  cord 
extending  from  the  margin  of  the  foramen  magnum 
to  the  pons  Varolii.  In  shape  it  resembles  a  quadri- 
lateral pyramid,  with  its  base  above  and  its  apex 
below.  The  ant.  surface  presents  a  median  fissure, 
not  so  deep  as  that  in  the  cord;  below  it  is  inter- 
rupted by  the  decussation  of  the  ant.  pyramids; 
above  it  terminates  at  the  pons,  in  &  foramen  csecum. 
The  ant.  tracts  of  the  cord  here  presents  two  bodies, 
which  are  called,  from  their  shape  and  position, 

The  anterior  Corp.  Pyramidalia. 

These  bodies  are  as  long  as  the  medulla,  and  lie 
on  each  side  o^  the  ant.  fissure;  they  commence  be- 
low by  their  narrow  extremities,  which  is  about  a 
line  and  a  half  in  thickness,  and  ascend,  gradually 
diverging  to  the  pons,  where  they  are  twice  that  in 
size;  they  then  suddenly  diminish  to  pass  above  that 
substance.  The  c.  pyram.  are  composed  of  white 
fasciculi,  and  appear,  although  considered  by  Ro- 
lando as  indistinct  superadded  bodies,  to  be  the  ant. 
tracts  of  the  cord,  augmented  by  fresh  nervous 
matter. 

The  decussation  of  the  ant.  Pyramids. 

This  remarkable  interchange  of  filaments  of  the 
anterior  pyramids  takes  place  about  the  lines  below 
the  pons,  it  is  formed  by  three  or  four  large  fasci- 
culi, which  regularly  and  successively  intercross. 
The  decussation  comprehends  the  ant.  two-thirds  of 
the  medulla,  and  also  takes  place  from  before,  back- 


180  FILAMENTA   ARCIFORMIA. 

wards,  as  the  ant.  portion  of  the  ant,  tract,  or  pyra- 
mid of  one  side,  may  be  traced  backwards  to  be  con- 
tinuous with  the  more  lateral  fasciculi  of  the  other. 
No  other  decussation  exists  in  the  medulla. 

Corpora  Olivaria. 

These  two  bodies  are  situated  external  and  some- 
what posterior  to  the  ant.  pyramids.  They  are  two 
white  oval  eminences  about  six  lines  long,  embedded 
to  half  their  diameter  in  the  medulla;  in  fact,  they 
are  inserted  between  the  anterior  and  post,  tracts, 
and  are  only  separated  from  each  other  at  the  median 
line  by  antero-poster.  transverse  filaments,  the  con- 
tinuations of  which  (fila.  arciformia)  bind  them,  as  it 
were,  in  their  situation:  they  contain  a  layer  of  gray 
matter,  crumpled  into  a  kind  of  concentric  frill. 

Corp.  Restiformia;  post,  pyramids;  infer.    Cerebellar 

Peduncles. 

The  posterior  tracts  of  the  cord  bear  these  titles; 
they  ascend  diverging  on  the  post,  surface  of  the 
medulla,  till  they  reach  the  cerebellum.  The  post, 
fissure  is  converted  into  a  triangular  depression 
(fourth  ventricle]  by  their  divergence.  This  ventri- 
cle, like  the  post,  fissure,  is  lined  by  cineritious  mat- 
ter, marked  by  a  few  medullary  stride,  so  as  to  bear 
altogether  a  vague  resemblance  to  a  pen  (hence 
calamus  scriptorious ;)  a  median  furrow  represents 
the  stem,  the  medullary  strise  the  feather,  and  the 
commencement  of  the  divergence  the  point. 

Filamenta  Arciformia, 

a  term  given  by  Santorini  to  some  medullary  filaments 
leading  from  the  anterior  to  the  posterior  tracts;  they 
are  important,  because  they  show  that  the  infer,  cere- 
bellar  peduncles  are  not  formed  solely  o"  the  post, 
tracts.  The  antero-post.  fibres,  before  mentioned, 
wind  horizontally  round  the  ant.  pyramids,  and  pass, 


CRURA   CEREBRI.  181 

one  set  of  fibres  immediately  below  the  corp.  olivaria, 
and  another  on  the  inner  side  of  those  bodies,  to  the 
corp.  restiformia.  Similar,  but  deeper  seated,  fibres 
are  described  by  Mr.  Solly,  to  cross  and  obliterate  the 
post,  cineritious  line,  and  then  join  the  restiform 
bodies. 

Fasciculi  Innominati. 

When  the  ant.  and  post,  pyramids  are  removed,  a 
dense  grayish  white  substance  is  seen  to  occupy  each 
half  of  the  cord;  like  the  olives,  they  are  only  sepa- 
rated by  the  ant.  post,  fibres.  This  substance,  which 
is  continuous  with  the  corresponding  lateral  tract, 
is  prolonged  to  the  optic  thalami,  &c. 

Isthmus. 

The  medulla  oblongata  is  connected  to  the  cerebrum 
and  cerebellum  by  certain  prolongations  whichoccupy 
an  intermediate  situationbetween  them.  The  isthmus 
comprises  the  crura,  or  pedunc.  cerebri,  the  contin.  of 
tkefascic.  innom.  the  super,  and  middle  peduncles  of  the 
cerebellum,  ports  Varolii,  tuber cula  quadrigemina,  and 
valve  of  Vieussens. 

The  pons  Varolii  is  a  mass  of  medullary  matter  of 
a  square  shape,  resting  upon  the  basilar  process  of  the 
occip.  bone,  and  supporting  the  anterior  pyramids  in 
their  passage  to  become  the  crura  cerebri.  Its  ant. 
and  post,  edges  are  free,  but  latterally  it  ascends  on 
each  side  of  the  crura  to  constitute  the  middle  pedun- 
cles of  the  cerebellum.  A  section  of  the  pons  shows  it  to 
be  composed  of  antero-posterior  and  transverse  me- 
dullary fibres,  intermixed  with  gray  matter,  which 
gives  each  slice  a  striated  appearance;  the  former 
fibres  belong  to  the  crura,  the  latter  to  the  middle  pe- 
duncles. The  inferior  surface  is  marked  by  a  groove, 
which  is  caused  by  the  projection  of  the  two  corp. 
pyramidalia;  it  generally  lodges  the  basil,  art. 

The  peduncles  of  the  cerebrum,  or  crura  cerebri.  are 
16 


182     TUBERCULA  QUADRIGEMINA. 

two  Irirge  white  round  cords  about  six  inches  long, 
which  continue  the  ant.  pyramids  in  the  cerebrum. 
They  diverge  in  proceeding  to  that  organ,  leaving  a 
triangular  space,  which  anter.  is  occupied  by  the  corp. 
inammil.  and  tuber,  cinereum,  and  poster,  by  the  inner 
portion  of  the  fascic.  innom.  Each  crus  is  often  in- 
tersected by  two  perpendicular  white  tracts,  one  from 
the  testes  and  valve  of  Vieussens,  the  other  from  the 
inner  surface  of  the  crura.  The  crura  are  separated 
from  the  fascic.  innom.  by  a  stratum  of  dark  gray 
matter  (locus  niger;}  their  size  is  strictly  relative  to 
that  of  the  corresponding  hemispheres. 

Peduncles  of  the  cerebellum.  The  inferior  are  the 
two  corp.  restiform,  strengthened  by  the  fili.  arci- 
form.  the  middle  are  constituted  by  the  prolongations 
of  the  pons,  which  might  be  called  their  commissure; 
the  superior,  pedunc.  processus  cerebelad.  testes:  inter- 
cerebral  commissure,  are  two  lamellae  which  arise  in 
the  substance  of  the  lateral  lobes  of  the  cerebellum, 
on  each  side  of  the  median  line,  and  extend  upwards 
and  forwards,  apparently  to  terminate  in  the  testes. 
They  form  the  ceiling  of  the  aqueduct  of  Sylvius,  and 
their  inner  edges,  which  are  proximate,  are  united 
by  the  valve  of  Yieussens. 

Valve  of  Vieussens.  A  thin  semi-transparent  la- 
mella, which  unites  the  adjoining  edges  of  the  sup. 
cerebellar  peduncles.  It  also  covers  the  aqueduct 
of  Sylvius. 

Tubercula  Quadrigemina.  These  are  four  roundish 
eminences,  placed  two  on  each  side  of  the  median  line, 
behind  the  thalami ;  the  anterior  two  are  called  nates, 
the  posterior  two  testes.  The  former  are  oblong,  and 
of  a  grayish  colour,  the  latter  are  rounder,  and  more 
inclined  to  white.  In  animals  they  constitute  the 
optic  tubercles,  and  are  in  some  joined  into  a  single 
pair;  they  are  single  in  the  foetus,  and  in  the  adult 
the  separation  is  not  complete.  The  nates  are  united 
to  the  thalami,  and  the  testes  to  the  intercerebral 


FOURTH  VENTRICLE.  183 

commissure.  On  the  outer  side  of  the  thalami,  a  lit- 
tle anterior  and  below  the  tubercula  quadrigemina,are 
two  little  swellings  called  corpus  geniculatum,  externum 
and  internum,  the  lateral  tracts  strengthened  by 
fascicul.  innom.  and  a  fasciculus  from  each  c.  oliv. 
terminate  in  these  tubercles  and  thalami — the  whole 
may  therefore  be  considered  as  one  connected  system. 

Cerebellum. 

The  cerebellum  is  placed  in  the  inferior  occipital 
fossae,  beneath  the  teritorium,  which  separates  it  from 
the  posterior  lobes  of  the  brain.  It  is  elliptical  in 
shape,  and  composed  of  two  symmetrical  halves,  or 
lobes,  united  at  their  fore  part  by  an  intervening  me- 
dian lobe.  The  lateral  lobes  are  separated  behind, 
and  below,  by  a  median  fissure,  which  receives  the 
falx  cerebelli;  below  and  in  front,  the  fissure  dilates 
into  a  notch,  which  partly  encloses  the  back  of  the 
medulla  oblongata.  When  the  lateral  lobes  are  pulled 
apart,  the  median  lobe  is  seen  continuous. on  each  side 
with  the  former,  and  its  two  halves  united  by  a  promi- 
nent median  raphe. 

The  Super.  Vermiform  process  is  this  raphe  on  the 
upper  surface  of  the  lobe ;  it  is  prominent  in  front, 
and  covers  the  valve  of  Vieussens;  behind  it  is  almost 
lost,  where  it  joins  the  infer,  vermiform  process,  or 
under  part  of  the  raphe,  on  the  back  of  the  lobe. 
The  Infer.  Vermiform  P.  is  marked  by  a  few  rings,  it 
is  seen  in  the  middle  of  the  notch,  and  forms  the 
post,  paries  of  the  fourth  ventricle,  into  which  pro- 
ject several  unimportant  eminences,  designated  by 
a  few  meaningless  terms. 

The  Fourth  Ventricle. — This  is  a  rhomboid  shaped 
cavity,  extending  from  the  aqueduct  of  Sylvius,  by 
which  it  communicates  with  the  third  ventricle  to  the 
pointof  the  calamus,  where  it  presents  an  orifice  leading 
into  the  sub-arachnoid  cellular  tissue.  It  is  bounded 
below  and  in  front  by  the  fascia  innom.;  laterally  by 


184  CORPUS    RHOMBOIDEUM. 

the  peduncles  of  the  cerebellum,  above,  by  the  sup. 
peduncles  of  the  cerebellum,  valve  of  Vieussens,  me- 
dian lobe,  and  inf.  vermiform  process,  and  neurilema 
of  the  cord.  The  Aqueduct  of  Sylvius  runs  beneath 
the  valve  and  super,  pedunc.  to  the  third  ventricle. 
The  inf.  orifice  is  rendered  interesting  by  the  recent 
researches  of  Magendie,  on  the  seat  of  the  cerebro- 
spinal  fluid. 

The  superficies  of  the  lobes  of  the  cerebellum  is 
grooved  by  numerous  horizontal  curved  lines,  which 
divide  the  organ  into  a  number  of  segments  and  lamel- 
lae, analogous  to  the  convolutions  of  the  cerebrum,  laid 
one  on  the  other  like  the  leaves  of  a  book.  The  con- 
tinuity of  these  lamellae  is  not  interrupted  at  the  me- 
dian lobe,  but  are  merely  drawn  out  of  their  direction 
as  they  pass  from  one  lateral  lobe  to  the  other;  the 
antero-post.  vertical  section  of  the  median  lobe  shows 
its  arbor  vitse.  This  appearance  is  produced  by  two 
medullary  trunks,  super,  and  inf.  springing  from  a 
central  medullary  nucleus,  and  dividing  into  many 
orders  of  branches.  The  primary  branches,  six  in 
number,  correspond  to  so  many  segments  of  the  organ; 
each  segment  divides  into  smaller  segments,  lamellae, 
and  lamellules ;  the  latter  are  extremely  irregular.  A 
stratum  of  cineritious  substance  invests  these  divi- 
sions, and  dips  in  the  intervals  between  them.  Similar 
sections  of  the  lateral  lobes  display  an  arbor  vitoe,  with 
branches  of  the  same  character  to  each  of  them.  By 
attentive  examination,  the  nuclei  and  their  medullary 
ramifications,  are  discovered  to  be  composed  of  medul- 
lary plates,  two  of  which,  at  least,  enter  into  the  forma- 
tion of  the  smallest  lamellule.  In  the  centre  of  each 
of  the  lateral  nuclei  is  a  small  round  body,  corpus 
rhomboideum,  or  ganglion  of  the  cerebellum,  resem- 
bling the  c.  olivaria,  particularly  in  the  arrangement 
of  the  stratum  of  gray  matter  which  it  contains.  The 
peduncles  of  the  cerebellum,  three  on  each  side,  en- 
ter into,  or  proceed  from  the  lateral  nuclei. 


OPTIC    TRACTS.  185 


Cerebrum. 

The  cerebrum  is  that  part  of  the  nervous  mass 
which  fills  the  entire  cranium,  excepting  the  inferior 
occipital  fossae.  The  greater  part  of  the  brain  is 
composed  of  convolutions,  which  spring  as  it  were 
from  the  isthmus,  situated  on  the  basilar  process 
and  body  of  the  sphenoid,  and  extend  in  every  di- 
rection till  they  entirely  fill  every  corner  of  the 
cranium.  The  superior  surface  of  the  brain  is  di- 
vided into  two  symmetrical  lateral  halves,  or  hemis- 
pheres^ by  a  deep  median  fissure,  which  receives  the 
falx  major.  The  whole  of  this  surface,  and  those  of 
the  hemisphere  next  the  falx,  are  marked  by  longi- 
tudinal elevations  and  depressions  (Circumvolutions 
and  sulci, )  which  have  their  corresponding  depres- 
sions, digital  fossse,  and  elevations  on  the  interior  of 
the  skull.  The  greater  part  of  the  infer,  surface  is 
also  formed  by  the  convolutions  of  the  hemispheres, 
which  are  here  subdivided  into  three  lobes:  the  ant. 
lobes  rest  upon  the  orbitar  processes  of  the  frontal 
and  smaller  wings  of  the  sphenoid  bone ;  the  middle 
lobes  are  lodged  in  the  sphenoidal  fossse,  the  post, 
lobes  on  the  tentorium.  The  ant.  are  separated  from 
the  middle  by  a  deep  fissure  (Sylvii;)  but  the  line  of 
demarkation  between  the  middle  and  the  posterior 
lobes  is  merely  a  faint  line,  produced  by  the  upper- 
edge  of  the  petrous  bone.  The  anterior  and  poste- 
rior lobes  are  only  separated  by  the  ant.  and  pos- 
terior continuations  of  the  great  median  fissure ;  but 
the  middle  lobes  have  between  them,  resting  upon 
the  basilar  process  and  body  of  the  sphenoid,  the 
isthmus  and  several  remarkable  eminences,  seen  on 
the  base  of  the  brain:  viz. 

Optic  Tracts. — Two  fasciculi  of  white  matter,  which 
arise  on  each  side  of  the  corp.  genie,  ext.,  wind  round 
each  crus  at  the  point  where  it  terminates  in  the  cor- 
pus striatum,  and  then  run  inwards  and  forwards  to 
16* 


186  PITUITARY   GLAND. 

form  the  commissure  of  the  optic  nerves  on  the  olivary 
process  of  the  sphenoid  bone.  These  fasciculi,  with 
the  crura  cerebri,  intercept  a  lozenge-shaped  space, 
which  contains  the  fascic.  innominati,  c.  mamtnillaria, 
tuber,  cinereum,  infundibulum,  and  pituitary  gland. 

Interpeduncular  space ;  or  space  left  by  the  diver- 
gence of  the  crura,  is  occupied  behind  by  the  lower 
surface  of  the  fasciculi  innom.,  in  front  by  the  c. 
mam. 

Corpora  Mammillaria. — Two  small  round  white 
eminences,  situated  between  the  crura,  their  ant.  sur- 
face imbedded  in  the  tuber,  cinereum, 4 heir  posterior 
in  the  fascic.  innom.  Although  tolerably  distinct  be- 
low, they  are  united  above  by  a  soft  gray  substance, 
which  forms  part  of  the  floor  of  the  third  ventricle. 
They  are  composed  of  a  central  portion  of  gray,  co- 
vered by  a  cortex  of  white  matter,  apparently  derived 
from  the  anterior  pillars  of  the  fornix. 

Tuber  cinereum. — A  soft  gray  substance  which  fills 
the  interval  between  the  corpora  mammil.  and  the 
optic,  fascic.  and  their  commissure.  It  is  a  continua- 
tion of  the  soft  substance  which  unites  the  c.  mam. 
and  with  it  forms  part  of  the  floor  of  the  third  ven- 
tricle. 

Infundibulum. — A  reddish  cord,  about  two  inches 
in  length,  directed  downwards  and  forwards  from 
the  tuber  cinereum,  to  the  ant.  lobe  of  the  pituitary 
gland,  to  which  its  apex  is  attached.  It  contains  a  fun- 
nel-shaped canal,  which  above  commun.  with  the 
third  ventricle,  but  ceases  at  the  gland.  It  is  com- 
posed of  a  cylinder  of  fibrous  pia  mater,  lined  by  the 
same  soft  gray  substance  as  is  seen  in  the  third  ven- 
tricle. 

Pituitary  Gland. — A  small  body  of  grayish  white 
substance,  weighing  from  five  to  ten  grains;  it  is  si- 
tuated in  the  sella  turcica  of  the  sphenoid  bone,  where 
it  is  confined  by  the  circular  and  cavernous  sinus,  and 
a  fold  of  dura  mater.  It  is  composed  of  an  anterior 
larger,  and  post,  smaller  lobe,  separated  by  a  fibrous 


FISSURE   OF    SYLVIUS.  187 

membrane.  They  both  contain  numerous  small 
vessels. 

The  commissure  of  the  optic  nervesbeing  removed, 
the  anterior  part  of  the  floor  of  the  third  ventricle 
is  exposed ;  it  is  formed  by  that  soft  gray  substance 
which  is  a  continuation  of  the  tuber  cinereum,  it  is 
covered  by  the  neurilema  of  the  optic  nerves,  which 
seem  to  derive  a  few  filaments  from  it.  A  little 
more  in  front  is  the  ant.  reflected  extremity  of  the 
corp.  callosum,  joining  the  anterior  lobes  of  the 
brain ;  still  more  in  front  the  ant.  and  inf.  portion 
of  the  great  median  fissure. 

Behind  the  pons  Varolii  is  the  post,  and  inner, 
ext.  of  the  great  median  fissure,  which  when  widened, 
shows  the  post,  extremity  or  bulb  of  the  c.  callosum, 
uniting  the  post,  lobes.  Between  the  bulb  and  the 
upper  surface  of  the  c.  quadrigemina  is  a  fissure, 
where  the  pia  mater,  as  the  tela  choroidcs,  enters  the 
ventricles.  This  is  the  fancied  situation  of  Bichat's 
celebrated  arachnoid  foramen,  which  does  not  exist 
(Cruveilhier.)  Here  also,  surrounded  by  the  tela 
choroides,  is  the  pineal  gland.  The  pia  mater  also 
enters  the  ventricles  by  another  fissure,  (Grande 
fente  celebrale,  Bichat,)  which  extends  on  each  side, 
from  the  extremity  of  the  former, to  the  fissure  of 
Sylvius.  It  enters  the  lateral  ventricle  between  the 
hemisphere  and  outer  sides  of  the  thalamu^s.  It 
only  admits  the  pia  mater. 

Fissura  Sylvii. — The  fissure  corresponds  to  the 
wing  of  Ingrassias,  and  commences  at  the  ant.  end 
of  the  grande fente,  extending  outwards,  so  as  to  form 
a  deep  interval  between  the  ant.  and  middle  lobes. 
It  contains  the  middle  arteries  of  the  cerebrum. 
The  angle  of  the  middle  lobe,  formed  by  the  junction 
of  the  two  above-mentioned  fissures  is  called  subs, 
perforata:  it  is  white,  and  pierced  by  numerous 
small  vessels. 


188  THE  FORNIX. 


INTERNAL    CONFORMATION    OF    THE    BRAIN. 

Corpus callosum,  (grand transvers e commissure:)  (ex- 
posed by  a  horizontal  section  on  a  plain  a  little  above 
it,  or,  by  separating  the  hemispheres  ;)  it  is  a  stratum 
of  medullary  matter,  about  three  and  a  half  inches 
long,  uniting  the  two  hemispheres,  at  the  bottom  of 
the  median  fissure.  The  upper  surface,  convex,  pre- 
sents a  median  furrow  produced  by  two  parallel 
longitudinal  strata  of  white  matter,  formed  by  the 
arteries  resting  here;  under  these  are  perceptible 
numerous  transverse  fibres,  of  which  this  commis- 
sure is  principally  composed.  The  infer,  surface, 
concave,  covers  the  lateral  ventricles,  and  also  pre- 
sents longitudinal  fasciculi;  anteriorly,  in  the  median 
line,  it  receives  the  septum  lucidum,  sent  up  from  the 
fornix;  posteriorly  it  joins  the  latter  body,  and  ter- 
minates just  above  the  c.  quad,  in  a  bulbous  extre- 
mity, which  unites  the  post,  lobes:  anteriorly  it  is  re- 
flected over  the  c.  striata  and  terminates  beneath  them 
just  in  front  of  the  third  ventricle,  where  it  unites 
the  ant.  lobes.  Two  white  fasciculi  (peduncles  of  the  c. 
cal.)  run,  parallel  to  the  optic  fasciculi,  from  this 
extremity  to  the  subs,  perforata  before  mentioned, 

Fornix;  longitudinal  commissure. — A  triangular 
medullary  arch  in  the  lateral  ventricles,  resting  upon 
the  thalami.  It  is  composed  of  two  lateral  fasciculi 
joined  in  the  median  line.  The  apex  of  the  fornix  ter- 
minates in  two  fasciculi,  (ant.  pillars,)  or  continua- 
tions of  the  lateral  fasciculi,  which  arch  over  the  fore 
part  of  each  thalamus  as  the  corpus  callosum  did  over 
the  c.  striata  ;  descend  between  those  two  bodies, 
through  the  gray  matter  on  the  sides  of  the  lateral 
ventricles  and  behind  the  ant.  commissure,  to  the  c. 
mammillaria,  to  form  the  medullary  cortex  ;  the  post, 
angles  are  continued  as  thepost. pillars,  outwards  and 
downwards  in  the  lateral  ventricles,  to  form  the  corp. 
fimbriata.  The  base  is  attached  to  the  bulb  of  the  corp. 


CORPUS   STRIATUM.  189 

callosum.  Between  the  upper  surface  of  the  thala- 
mus  and  ant.  pillar  on  each  side,  a  space  (for.  Mon- 
ro)  is  left,  by  which  each  lateral  communicates  with 
the  third  ventricle. 

Septum  Lucidum. — The  triangular  interval  between 
the  fornix  and  corp.  callosum  is  closed  by  two  deli- 
cate semi-transparent  lamellse,  which  are  sent  up 
from  the  contiguous  edge  of  each  half  of  the  fornix, 
to  the  under  and  fore  part  of  the  corpus  callosum. 
The  interval  beween  them  is  called  the  fifth  ventri- 
cle, which  sometimes  contains  a  few  globules  of 
fluid  :  it  does  not  communicate  with  the  other  ven- 
tricles. The  septum  lucidum  separates  the  lateral 
ventricles. 

Lateral  Ventricles. — Exposed  by  dividing  the  corp. 
callosum  on  each  side  of  the  septum  lucidum.  They 
commence  in  each  anterior  lobe  a  little  before  the 
beginning  of  the  third  ventricle,  forming  the  anterior 
cornu,  run  upwards  and  backwards,  and  a  little  be- 
yond the  termination  of  the  third  vent.,  turn  round 
the  post,  part  of  the  thalamus,  beneath  which  they 
are  reflected,  to  terminate  in  the  middle  lobe,  close 
to  the  fissure  of  Sylvius,  only  a  little  below  and  be- 
hind where  they  commenced,  forming  the  inferior 
cornua.  At  the  point  of  reflection  it  sends  a  pro- 
longation (digital  cavity)  into  the  posterior  lobe, 
forming  the  posterior  cornua. 

The  superior,  or  straight  portion  of  the  lat.  ventricle. 
— The  floor  of  this  portion  is  formed  by  the  upper 
surfaces  of  the  corresponding  corp.,  striatum,  and 
optic  thalamus. 

Corpus  Striatum. — A  grayish,  pyriformbody  deeply 
embedded  in  the  fore  part  of  the  floor  of  the  lateral 
ventricle.  Its  largest  extremity  lies  in  front  of  the 
thalamus,  but  behind  it  runs  tapering  along  the  outer 
side  of  that  body  to  the  point  where  the  lateral  ven- 
tricle begins  its  reflection.  Internally  it  corresponds 
to  the  gray  matter  which  forms  the  sides  of  the  ant. 


190  THIRD    VENTRICLE. 

part  of  the  third  ventricle,  and  to  the  outer  side  of  the 
thalamus.  Below,  it  sinks  deeply  into  the  post,  and 
inner  part  of  the  anterior  lobe.  Its  interior  presents 
a  remarkably  striated  appearance,  produced  by  the 
diverging  fibres  of  the  cerebrum,  of  which  it  is  sup- 
posed to  be  the  great  ganglion. 

Thalamus  nervi  optici. — An  oblong  brownish-white 
body,  situated  in  the  floor  of  the  lateral  ventricle, 
behind  and  internal  to  the  c.  striatum.  Its  ant.  ex- 
tremity is  separated  from  the  c.  striatum  by  the 
ant.  pillars  of  the  fornix,  and  its  outer  side  from 
that  body  by  the  tenia  semicircular  h.  Its  inner  sur- 
face forms  part  of  the  side  of  the  lateral  ventricle. 
It  is  covered  by  the  tela  choroides  and  inf.  surface 
of  the  corresponding  lateral  stratum  of  the  fornix  ; 
its  interior  is  composed  of  gray  matter. 

The  tenia  semicircularis  is  a  narrow  white  band, 
separating  the  corp.  striat.  from  the  thai. :  it  is 
covered  by  a  vein  which  is  enclosed  in  a  fold  of  the 
lining  membrane  of  the  ventricle. 

In  the  inf.  or  reflected  portion  of  the  lat.  ventricle,  is 
1,  hippocampus  majors  cornu  ammonia — a  portion  of 
a  convolution  projecting  from  the  floor;  2,  corpus 
fimbriatum,  a  narrow  dense  band,  a  prolongation  of 
the  post,  pillar,  or  angle  of  the  fornix  which  runs 
on  the  hippocampus. 

In  the  post,  portion,  or  digital  cavity,  is  seen  the 
hippocampus  minor,  also  a  projecting  convolution.  It 
is  connected  to  the  h.  major  by  a  narrow  band  which 
is  also  connected  with  the  fornix. 

Third   Ventricle. 

This  is  merely  a  fissure  separating  the  optic  thalami. 
Behind  and  above, its  sides  are  formed  by  these  bodies, 
but  before  and  below  it  is  lined  by  a  peculiar  soft  gray 
matter,  which  is  continuous  with  the  tuber  cinereum. 
The  floor,  concave,  is  constituted  posteriorly  (between 
the  crura, )  by  the  fascic.  innom. ;  in  the  middle  by  the 
tuber  cinereum,  c.mammil.  and  infundib. ;  anteriorly 


PIA    MATER.  191 

by  the  reflected  portion  of  the  c.  callosum.  Its  sides 
are  united  by  three  commissures — viz.  1,  com.  mollis, 
a  soft  gray  substance  like  the  tuber  ciner.,  situated 
just  in  front  of  the  thalami;  2,  com.  ant.  a  white  cord 
just  in  front  of  the  ant.  pillars  of  the  fornix,  uniting 
the  thalami ;  3,  com.  post,  a  similar  cord  uniting  those 
bodies  just  in  front  of  the  t.  quadrigemina. 

The  aqueductus  Sylvii  is  a  canal  leading  under  the 
tuber  quadri.  from  the  third  to  the  fourth  ventricle. 
The  third  ventricle  contains,  1,  the  opening  of  this 
aqueduct ;  2,  that  of  the  infundibulum ;  and  3,  4,  the 
foramen,  or  foramina  of  Monro. 

Pineal  Gland. — A  small  conical  body  resting  on 
the  fissure  separating  the  t.  quadri.,  just  behind  the 
post,  commissure.  Its  base  is  attached  to  the  tha- 
lami, by  two  peduncles,  which  are  also  attached  to 
a  white  stratum  (Pineal  comm.,)  which  extends  be- 
tween the  thalami,  above  the  post,  commissure.  It 
frequently  contains  irregular  concretions  of  phos. 
lime  and  animal  matter  (Pfaff,)  and  is  closely  in- 
vested by  the  tela  choroides. 

Membranes  of  the  Brain. 

The  surfaces  of  the  brain  are  supplied  with  blood 
by  a  vascular  membranous  network,  (pia  mater,) 
which  dips  between  all  the  convolutions,  and  enters 
the  ventricles,  where  it  forms  thick  vascular  meshes, 
(plexus  choroides  ^)  which  also  receives  additional  arte- 
rial branches  from  the  base  of  the  brain.  The  tela 
choroides  spreads  over  the  third  ventricle  and  tha- 
lami, but  under  the  fornix,  the  pia  mater  enters  into 
post,  fissure  to  form  it:  it  dips  into  the  third  ventri- 
cle to  form  its  plexus  choroides,  and  enters  the  lat. 
ventricles  through  the  foramen  of  Monro  on  each 
side  to  form  a  choroid  plexus  for  each  of  them. 
The  pia  mater  also  enters  the  lat.  vent,  through  the 
grandefente.  The  plexus  of  the  third  passes  through 
the  aqued.  of  Sylvius,  to  form  the  plexus  ch.  of  the 
fourth  ventricle. 


192  SINUSES    OF   BRAIN. 

Dura  Mater. 

This  is  a  strong  fibrous  membrane,  which,  lines  the 
skull  as  a  periosteum  to  the  bones,  and  sends  septa 
to  separate  and  support  the  different  divisions  of  the 
nervous  mass.  The  construction  of  these  partitions 
is  best  understood  by  supposing  a  fold  of  membrane 
to  be  pinched  up  on  the  line  occupied  by  these  septa, 
and  drawn,  more  or  less,  into  the  interior  of  the 
cavity.  The  falx  major  separates  the  two  hemis- 
pheres; it  commences  by  its  point  being  attached  to 
the  crista  galli  of  the  ethmoid  bone,  and  its  base  is 
continuous  on  each  side  with  the  upper  lamina  of 
the  tentorium.  Its  upper,  or  cranial  edge,  convex, 
is  attached  along  the  inner  mesial  line  of  the  cranium, 
and  contains  the  super,  long,  sinus;  its  lower  edge, 
concave,  is  free,  and  contains  the  inf.  long,  sinus. 
The  tentorium  separates  the  cerebrum  from  the  cere- 
bellum ;  its  circumference,  or  cranial  edge,  corres- 
ponds to  the  lateral  occipital  grooves,  upper  edge  of 
the  petrous  bone,  and  it  term,  at  the  post,  clinoid  pro- 
cesses ;  its  inner  crescentic  edge  surrounds  the  me- 
dulla oblongata,  its  horns  being  prolonged,  under  the 
terminations  of  the  outer  edge,  to  the  ant.  clinoid  pro- 
cesses. The  falx  cerebelli  separates  the  lateral  lobes  of 
the  cerbellum :  its  upper  portion,  or  base,  is  continu- 
ous with  the  inf.  lamina  of  the  tent. ;  it  terminates 
by  a  pointed  end  at  the  foramen  magnum. 

The  dura  mater  consists  of  two  membranes,  the 
inner  one  forming  the  septa,  the  outer  one  remain- 
ing attached  to  the  bone;  it  is  lined  internally  by  a 
reflexion  of  the  arachnoid  membrane,  externall}7  it 
is  closely  connected  to  the  inner  surface  of  the 
bones  of  crunium  by  numerous  vessels. 

The  sinuses,  fifteen  in  number,  are  composed  of 
the  inner  membrane  of  a  vein  enclosed  between 
these  two  layers. 

1,  The  super,  longitudinal  sinus,  corresponds  to  the 


DURA    MATER.  193 

cranial  edge  of  the  falx :  it  contains  the  cordse  Willisii, 
which  are  said  to  preserve  its  venous  orifices  patent ; 
2,  infer,  longitudinal  sinus,  inf.  edge  of  the  falx;  3, 
4,  lateral  sinuses,  cranial  edge  of  the  tentorium;  5, 
straight  sinus,  contin.  with  the  inf.  long,  sinus,  runs 
in  the  diamond  shaped  canal,  between  the  conjoined 
laminse  of  the  falx  major,  minor,  and  tentorium ;  6,  7, 
cavernous  sinuses,  on  each  side  of  the  sella  turcica ; 
traversed  by  the  third,  fourth,  first  branch  of  the  fifth 
and  sixth  pair  of  nerves ;  the  carotid  artery,  and  caro- 
tid plexus  of  the  sympathetic,  all  of  which  are  sepa- 
rated from  the  blood  by  the  venous  membrane;  8,  9,  inf. 
petrosal  sinus,  inf.  or  occipital  angle  of  the  petrous 
bone;  10,  transverse  sinus  joins  the  last  two  across  the 
basilar  process;  11,  12,  super,  petrosal  sinuses,  upper 
angle  of  the  petrous  bone;  13,  circular  sinus,  sur- 
rounds the  pituitary  gland,  communicating  on  each 
side  with  the  cavernous  sinuses;  14,  15,  occipital  si- 
nuses, occipital  foramen. 

The  straight  sinus  receives  the  inf.  long.,  s.  vena 
Galena,  and  the  inf.  and  middle  cerebral  and  cerebel- 
lar  veins.  The  petrous  sinuses  receive  the  cavernous, 
circular,  and  transverse  sinuses.  The  lateral  sinuses 
receive,  1,  the  super,  long,  s.,  straight  s.,  and  two  occi- 
pital sinuses,  opposite  the  occipital  tuberosity,  the 
conflux  being  termed  torcular  Herophili;  and  2,  the 
petrosal  sinus  at  some  point  of  their  course  to  termi- 
nate in  the  int.  jugular  veins. 

The  dura  mater  descends  through  the  foramen  mag- 
num, to  which  it  closely  adheres  in  the  vertebral  canal 
as  a  sheath,  which  encloses  the  spinal  cord,  and  forms 
a  distinct  sheath  for  each  pair  of  spinal  nerves.  It 
is  loosely  attached  by  means  of  distinct  ligamentous 
slips  to  the  post.  comm.  lig.,  but  a  peculiar  reddish 
semi-fluid  fat,  traversed  by  many  vessels,  separates  it 
from  the  arches  and  lig.  subflava ;  below  it  forms  a 
large  sac,  which  surrounds  the  chorda  equina,  and  is 
distended  by  the  cerebro-spinal  fluid.  A  large  space 

17 


194  STRUCTURE   OF   BRAIN. 

exists  between  the  sides  of  the  cord  and  sheath  also 
generally  filled  with  this  fluid. 

The  arachnoid  is  a  very  fine  serous  sac  placed  be- 
tween the  dura  mater  and  pia  mater.  It  covers  the 
convolutions,  and  is  also  carried  into  the  third  ventri- 
cle by  the  venae  Galeni,  through  the  post,  fissure, 
it  then  passes  into  the  other  ventricles  and  infundib. 
through  its  four  openings.  A  similar  sac  is  found 
between  the  spinal  cord  and  its  sheath  of  dura  mater. 
The  arachnoid  passes  from  one  convolution  to  the 
other  without  entering  the  sulci;  it  is  also  stretched 
from  the  tuber,  cin.  to  the  pons,  and  from  the  lobes  of 
the  cerebellum  to  the  cord,  large  corresponding  spaces 
are  thus  left  between  it  and  the  pia  mater,  with  which 
the  numerous  minor  spaces  between  the  convolutions 
and  ventricles  communicate.  The  whole  of  the  spaces 
are  filled  with  the  cerebro-spinal  fluid. 

The  arachnoid  membrane  presents  a  similar  ar- 
rangement in  the  spinal  canal  investing  the  inner 
surface  of  the  dura  mater,  and  the  outer  surface  of 
the  pia  mater,  and  forms  the  lig.  denticulata. 

Thepia  mater  is  the  immediate  investing  membrane 
of  the  cord,  it  is  much  more  dense  but  less  vascular 
than  that  of  the  brain. 

Structure  of  the  Brain. 

Each  hemisphere,  by  transverse  sections,  is  seen  to 
be  formed  by  a  large  central  nucleus  of  medullary 
matter  united  by  means  of  the  corpus  callosum.  Each 
nucleus  divides  into  three  segments,  which  subdivide 
into  the  convolutions.  The  convolutions,  unlike  the 
lamellae  of  the  cerebellum,  are  only  a  few  lines  (from 
nine  to  fourteen)  deep,  and  meander  in  various  direc- 
tions. In  size  and  sit.  a  few  of  them  only  are  constant, 
most  of  them  differ  greatly  in  different  brains.  Their 
use  is  to  augment  the  extent  of  surface  of  medullary 
matter,  and  thereby  obtain  a  more  extensive  stratum 
of  that  peculiar  gray  matter  which  is  supposed  to 
play  such  an  important  part  in  all  nervous  phenomena. 


LATERAL  TRACTS.  195 

Since  the  beautiful  theories  of  Gall  and  Spurz- 
heim,  which  have  given  a  peculiar  tone  and  direc- 
tion to  all  subsequent  researches  respecting  the  con- 
struction of  the  nervous  centres,  anatomists  are  ac- 
customed, in  describing  the  connections  and  relations 
of  the  diiferent  parts  of  the  nervous  system,  to 
employ  such  terms  as  origin,  divergence,  expansion, 
&c.,  terms  which  must  be  understood  only  as  expres- 
sive of  the  peculiar  views  of  the  various  authors  who 
make  use  of  them.  The  amount  of  our  present  real 
knowledge  of  the  construction  of  the  nervous  sys- 
tem may  be  stated  as  follows: — 

1.  The  anterior  tracts  of  the  cord  decussate,  by  the 
principal  part  of  their  filaments,  at  the  commencement 
of  the  medulla  oblongata,  and  may  then  be  traced 
upwards,  first  as  the  anterior  pyramids,  and  then  as 
the  crura  cerebri,  above  the  pons  Varolii,  forming 
the  diverging  fibres  of  the  cerebrum,  to  the  corpora 
striata;  further,  their  white  medullary  filaments  may 
be  traced  through  the  gray  substance  of  which  these 
bodies  are  composed,  and  to  make  use  of  the  figura- 
tive, from  the  side  opposite  to  that  at  which  they 
entered,  they  are  seen  to  diverge  forwards,  upwards, 
and  backwards,  so  as  to  compose  much  of  the  medul- 
lary centres  of  the  hemispheres,  finally  terminating 
by  being  lost  in  the  cortical  layer  of  gray  matter. 

2.  The  lateral  tracts  of  the  cord  becoming  fasciculi 
innom.,  in  the  medulla  oblongata,  and  strengthened 
by  two  fasciculi  from  the  olivary  bodies,  ascend  pa- 
rallel to  and  upon  the  upper  part  of  the  crura  (the 
separation  between  them  being  marked  by  the  locus 
niger)  to  be  continuous  without  any  line  of  demar- 
kation  whatever  with  the  thalami:    they  are  also 
connected  to  the  tuber  quadri.     From  the  opposite 
side  of  each  thalamus  white  diverging  fibres  are  seen 
to  arise,  and  diverge  in  all  directions,  intermixing 
with  the  posterior  fibres  from  the  corpora  striata, 
like  them  also  to  terminate  in  the  cortical  gray  layers 


196  STRUCTURE  OF  BRAIN. 

of  the  convolutions.     Some  fibres  from  the  thalami 
traverse  the  corp.  striata. 

3.  The  posterior  tracts  are  continued  in  the  medulla 
oblongata,  as  the  restiform  bodies,  or  inf.  cerebellar 
peduncles ;  these  may  be  still  further  traced,  with- 
out any  decussation,  to  the  central  nuclei  of  the  la- 
teral lobes  of  the  cerebellum,  where  they  pass  through 
the  corpus  dentatum  or  ganglion  of  the  cerebellum, 
and  thence  diverge  to  form  its  hemispheres.  Previous 
to  their  entrance  into  the  cerebellum  it  will  be  recol- 
lected that  they  are  joined  by  the  filament  a  arciformia. 

4.  The  convoluted  portion  of  the  hemispheres  is  thus 
composed  of  the  medullary  radiations  from  the  cen- 
tral nuclei,  or  corp.  striata  and  thalami,  covered  by 
a  layer  of  gray  matter. 

5.  The  cerebellum  is  composed  as  before  stated. 
The  nervous  system  is  made  up  of  two  symmetrical 

lateral  halves,  united  by  certain  medullary  strata 
called  commissures  ;  thus, 

6.  The  lateral  sides  of  the  cord  are  united  by  a 
uniform  layer  of  soft  white  matter,  seen  at  the  bottom 
of  the  ant.  median  fissure. 

7.  The  lateral  lobes  of  the  cerebellum  are  united,  1, 
by  the  middle  lobe,   the   raphe  of  which,  seen  as 
the  two  vermiform  processes,  indicates  that  it  also 
formerly  consisted  of  two  lateral  halves ;  2,  by  the 
pons  Varolii,   which  is   continued  upwards   round 
each   crus  cerebri,  as   the  middle  peduncles  of  the 
cerebellum,    to    the   central   medullary    nucleus  of 
each  lateral  lobe  of  that  body ;  3,  by  the  valve  of 
Vieussens. 

8.  The  central  nuclei  (c.  striata  et  thalami)  of  the 
hemispheres  are  united  by,  1,  the  ant.  commissure; 
2,  the  posterior  commissure;  and  3,  the  Pineal  com- 
missure. 

9.  The  two  hemispheres  are  united  by  the  great 
transverse  commissure,  or  corpus  callosum. 

10.  Each  hemisphere  is  united  in  its  diiferent  parts ; 
1,  by  the  inferior  longitudinal  commissure  or  fornix, 


STRUCTURE   OF   BRAIN.  197 

which  by  its  ant.  pillars  before,  and  its  post,  pillars 
behind,  is  connected  to  each  lobe ;  2,  by  the  superior 
longitudinal  commissure,  composed  of  longitudinal 
fibres,  which  run  in  the  substance  of  the  hemispheres 
in  the  same  curved  lines  as  (but  a  little  above)  the 
corpus  callosum,  and 

11.  The  cerebrum  and  cerebellum  are  united  by 
the  intercerebral  commissure,  or  superior  peduncles 
of  the  cerebellum. 

The  commissures  are  formed  by  the  transverse  or 
converging  fibres,  which  arise  in  the  external  cineri- 
tious  substance,  and  pass  inwards  to  the  opposite 
hemisphere. 

The  hemispheres  appear  to  be  composed  of  the  me- 
dullary striae  from  the  corpora  striata;  of  similar  striae 
from  the  thalami;  and  striae  which  are  continuous 
on  each  side  with  the  transverse  fibres  of  the  corpus 
callosum,  all  intermixing  and  radiating  in  various  di- 
rections till  they  arrive  at  the  surface  of  the  convo- 
lutions; the  latter  are  formed  by  an  outer  stratum  of 
gray  matter,  and  an  inner  medullary  stratum  thrown 
into  a  series  of  folds  (convolutions;)  each  convolution 
being  composed  of  a  rind  of  this  gray  and  white 
matter,  containing  the  terminal  ends  of  those  nume- 
rous white  striae  from  the  corp.  striata,  thalami,  and 
c.  cal. 

Comparative  anatomy  will,  in  some  degree,  assist 
in  rendering  our  knowledge  of  the  brain  a  little  more 
clear.  It  is  seen,  for  instan-ce,  that  the  brains  of 
some  animals,  especially  fishes,  are  composed  of  two 
linear  series  of  lobes,  which  answer  to  the  olfactory 
lobes,  corpora  striata,  thalami,  tubercula  quadrigeini- 
na  and  middle  lobe  of  the  cerebellum,  in  man.  In  ani- 
mals of  a  grade  still  lower  than  those  referred  to, 
the  brain  is  composed  of  little  nodules,  of  less  number 
and  size,  so  that  it  is  difficult  in  some  cases  to  distin- 
guish which  should  properly  be  called  thalamus,  &c.; 
but  enough  is  learned  by  such  a  comparative  consi- 


198  STRUCTURE   OF   BRAIN. 

deration  of  these  primitive  strata,  or  accumulations 
of  nervous  matter,  to  show  the  probable  use  of  the 
hemispheres  and  the  parts  relating  to  them.  The 
human  brain,  in  fact,  consists  of  certain  primitive 
nuclei,  covered  by  superadditions  of  nervous  matter 
in  the  shape  of  the  two  hemispheres.  If  the  organ  be 
traced  through  the  phases  which  it  presents  at  succes- 
sive periods  of  foetal  existence,  the  primitive  nuclei 
are  observed  to  become  gradually  covered  by  two  thin 
membranes  which  seem  to  spring  from  their  sides; 
they  represent  the  hemispheres:  it  is  not  until  the 
hemispheres  have  nearly  finished  their  progress  that 
the  convolutions  make  their  appearance. 

The  corpus  callosum,  fornix,  septum  lucidum,  the 
lateral  ventricles,  and  the  parts  they  contain,  as  the 
hippocampi,  corpus  fimbriatum,  are  dependents  of 
the  hemispheres,  and  therefore  are  never  found 
when  the  latter  are  absent. 

The  uses  of  the  following  parts  are  still  enveloped 
in  mystery: — 

1.  Corpora  albicantia,  absent  in  birds  and  reptiles, 
very  large  in  fishes;  supposed  to  be,  like  the  hippo- 
campi, a  convolution  in  a  different  form. 

2.  Pituitary  gland  and  infundibulum. 

3.  Pineal  gland,  or  conarium;  the  seat  of  the  soul 
(Descartes.)     A  plug  to  obstruct  the  orifice  leading 
from  the  third  to  the  fourth  ventricle  (Magendie.) 

4.  The  relative  uses  of  the  cineritious  and  medul- 
lary structures.     Until  a  period  subsequent  to  birth 
they  are  indistinguishable  from  each  other;  they  ap- 
pear to  be  formed  simultaneously,  and  only  acquire 
their  distinctive  characters  at  some  distant  period. 
It  would  not  be  unprofitable  to  take  a  general  view 
of  this  remarkable  gray  matter  in  its  various  relations 
to  the  medullary  substance,  but  we  have  only  space  to 
observe,  that  it  is  found  principally  at  the  central 
terminations  of  nerves,  and  other  medullary  media, 
which  may  thus  be  considered  as  mere  internuncii. 


ARTERIES  AND  VEINS  OF  BRAIN.        199 

The  brain  is  supplied  with  blood  by  the  int.  carotid 
and  vertebral  arteries ;  the  former  enter,  one  at  each 
side,  through  the  carotid  foramen,  in  the  petrous 
portion  of  the  temporal  bone,  pass  through  the  canal, 
and  ascend  by  the  side  of  the  sella  turcica;  they 
here  divide  into  the  anterior  and  middle  cerebral 
posterior  communicating  arteries.  The  anterior 
passes  forwards  and  inwards,  is  joined  to  its  fellow 
by  the  ant.  communicating  branch,  winds  round  the 
ant.  extremity  of  the  corpus  callosuni,  and  termin- 
ates in  the  callos.  art.  The  middle  passes  upwards 
and  outwards  into  the  bottom  of  the  fissure  of  Syl- 
vius, and  supplies  the  ant.  and  mid.  lobes.  The 
posterior  communicating  branch  passes  backwards 
to  join  the  posterior  cerebral  art.,  and  forms  the 
side  of  the  circle  of  Willis. 

The  vertebral  arteries  enter  by  the  foramen  mag- 
num, ascend  forwards  and  inwards,  and  unite  in 
front  of  the  pons  Varolii  to  form  the  basillar  art. 
This  ascends  along  the  groove  in  the  pons,  and  at 
its  upper  margin  divides  into  the  superior  art.  of 
the  cerebellum  and  post.  art.  of  the  cerebrum,  to 
their  destination  in  the  cerebellum  and  post,  lobe  of 
the  brain;  the  latter  joins  the  post,  communicating 
branch,  as  just  described,  and  thus  completes  the 
circle  of  Willis.  Each  vertebral  art.  gives  oif,  before 
forming  the  basilar,  two  branches,  the  anterior  and 
posterior  spinal  arteries ;  these  descend  along  the 
corresponding  surfaces  of  the  spinal  cord,  anasto- 
mosing with  similar  branches  from  the  deep  cervical, 
intercostal  and  lumbar  arteries,  and  the  inferior  ar- 
tery of  the  cerebellum  to  the  under  surface  of  this 
part.  The  blood  from  the  brain  is  collected  in  the 
sinuses,  and  is  returned  by  the  int.  jug.  vein;  the 
veins  from  the  Bpinal  marrow  form  numerous  venous 
plexuses  around  the  transverse  processes  of  the  ver- 
tebrae, and  empty  themselves  into  the  adjoining  ven- 
ous trunks. 


200  NERVES. 

DIVIDED    INTO    CEREBRAL,    SPINAL,    AND 
SYMPATHETIC. 

Spinal  Nerves. 

IT  has  long  been  considered  that  the  experiments 
of  Sir  C.  Bell  and  Magendie  have  left  no  doubt,  that, 
of  the  double  roots  by  which  each  pair  of  spinal 
nerves  is  attached  to  the  cord,  sensation  depends  on 
the  posterior  or  ganglionic  root,  and  motion  on  the 
anterior  ;  but  it  is  by  no  means  ascertained  that  they 
derive  such  powers  from  corresponding  tracts  of  the 
cord.  The  cord  is  stated  to  be  composed  of  an  an- 
terior or  motor  portion,  and  a  posterior  or  sensory 
portion,  which  are  joined  together  somewhere  in  the 
lateral  tract;  now  the  one  or  other  power  may  be 
fairly  assigned  to  that  point  where  the  anterior  and 
posterior  roots  are  respectively  attached ;  but  the 
precise  origin  of  them  is  by  no  means  determined. 
Cruveilhier  denies  the  existence  of  different  orders 
of  nerves ;  he  could  not  even  perceive  any  difference 
between  the  result  from  a  division  of  the  anterior, 
and  that  from  the  division  of  the  posterior  roots. 

The  spinal  nerves  are  thirty-one  in  number,  in- 
cluding the  sub-occipital.  There  are  eight  cervical, 
twelve  dorsal,  five  lumbar,  and  six  sacral. 

Origin  of  the  Spinal  Nerves. 

The  spinal  nerves  arise  by  two  linear  series  of  fila- 
ments from  the  anterior  and  posterior  cineritious  lines 
and  are,  therefore,  separated  by  the  lateral  tracts,  and 
the  ligamentum  donticulatum.  In  the  adult  they  can- 
not be  traced  into  the  anterior  of  the  cord,  so  as  to 
ascertain  their  precise  points  of  origin,  but,  through 
the  semitransparent  cord  of  a  foetus  seven  or  eight 
months  old,  numerous  delicate  nervous  filaments, 
which  compose  the  anterior  and  posterior  spinal 


POSTERIOR   CERVICAL   NERVES.  201 

nerves,  are  seen  to  traverse  the  central  gray  matte r, 
and  may  be  followed  even  to  the  posterior  tracts. 

Immediately  after  the  exit  from  the  cord,  the  fila- 
ments divide  into  sets  of  eight  or  ten,  which  converge 
so  as  to  form  one  of  the  roots  of  the  spinal  nerves. 
The  anterior  and  posterior  roots  soon  approximate, 
but  do  not  unite,  and  each  is  enclosed  in  a  distinct 
sheath  of  dura  mater. 

Differences  between  the  two  Roots. 

The  anterior  roots  are  smaller,  excepting  the  first, 
or  sub-occipital,  whose  anterior  root  is  the  larger, 
near  the  median  line,  and  their  filaments  are  not 
attached  to  the  cord  exactly  in  the  same  line.  They 
have  no  ganglions. 

The  posterior  roots  are  larger,  their  filaments  are 
attached  in  succession  to  the  posterior  cineritious  line, 
and  each  presents,  when  arrived  at  the  corresponding 
intervertebral  foramen,  a  characteristic  swelling  or 
ganglion,  which  is  situated  within  the  foramen. 

A  junction  of  the  two  roots  now  takes  place  ;  the 
anterior  root,  however,  is  not  entirely  free  from  the 
ganglion,  which  frequently  receives  several  filaments 
from  it. 

Branches  of  the  Spinal  Nerves. 

The  conjoined  cord  of  the  two  roots  divides.into, 
1,  a  middle  or  ganglionic  branch;  2,  a  posterior 
branch  ;  and,  3,  an  anterior  branch. 

The  ganglionic  branches  belong  to  the  sympathetic 
nerve. 

The  posterior  branches,  the  smaller,  excepting  the 
first  two,  supply  the  parts  on  the  back  of  the  trunk. 

The  anterior  branches  supply  the  fore  part  of  the 
trunk,  and  the  extremities. 

Post.  Branches  of  the  Cervical  Nerves. 
The  first  escapes  between  the  occipital  bone  and 


202  POSTERIOR   BRANCHES. 

atlas,  on  the  inner  side  of  the  vertebral  artery ;  it 
lies  in  the  triangle  formed  by  the  rect.  post,  major, 
and  obliqui,  which  it  supplies. 

The  second,  the  largest,  escapes  between  the  arches 
of  the  first  and  second  vertebrae,  beneath  the  lower 
edge  of  the  inf.  obliquus,  and  ascends  under  the  cer- 
vical muscles,  which  it  pierces  close  to  the»occipital 
artery,  to  ramify  with  it  on  the  post,  part  of  the 
cranium.  Ram.  to  the  adjoining  muscles. 

The  third,  arrived  between  the  two  complex!  mus- 
cles, divides  into  an  occipital,  and  transverse  or  cer- 
vical branch. 

The  fourth,  fifth,  sixth,  seventh,  and  eighth,  are 
much  smaller  than  the  former,  and  after  supplying 
the  cervical  muscles,  terminate  in  the  integuments. 
The  first,  second,  and  third,  also  form  a  species  of 
plexus,  beneath  the  complexi  muscles. 


Posterior  Branches  of  the  Dorsal  Lumbar  Nerves. 

The  eight  superior  branches  divide  into  external, 
or  muscular  branches,  which  subdivide  in  the  space 
between  the  sacro-lumbalis  and  longisshnus  dorsi 
muscles,  to  supply  those  m.,  &c.,  and  musculo  cuta- 
neous branches,  which,  after  a  curious  winding  course, 
pierce  the  latissimus  dorsi  near  the  spine,  and  run 
horizontally  outwards  to  the  skin. 

The  four  last  dorsal,  and  the  five  lumbar,  pierce 
the  common  mass  of  the  long  dorsal  muscles,  supply 
them,  and  then  wind  horizontally  round  the  loins, 
some  under  the  latissimus  dorsi,  and  some  between 
the  layers  of  abdominal  muscles,  which  they  pierce 
here  and  there,  to  terminate  on  the  skin  of  the  abdo- 
men. 

The  posterior  branches  of  the  sacral  nerves  pierce 
the  muscular  mass,  on  the  back  of  the  sacrum,  to  ra- 
mify in  the  skin  over  the  sacrum  and  nates. 


CERVICAL   PLEXUS.  203 

Anterior  Branches  of  the  Spinal  Nerves. 

CERVICAL  PLEXUS  ;  formed  by  the  ant.  branches  of 
the  first  (not  sub-occipital,)  second,  third,  and  fourth 
cervical  nerves.  The  first  and  second  at  their  exit 
from  the  vertebral  foramina  anas,  by  an  ascending  and 
descending  branch,  so  as  to  form  a  curious  loop 
around  the  transverse  process  of  the  atlas;  from  this 
loop  branches  supply  the  recti  muscles  and  anastomose 
with  the  first  cervical  ganglion  and  the  spinal  acces- 
sory. The  cervical  plexus  is  situated  under  the  post, 
edge  of  the  sterno-mastoid  muscle,  between  the  rec- 
tus  anticus  and  ins.  of  thesplenius  colli ;  it  is  covered 
by  adipose  tissue  and  lymphatic  glands.  Ram. 

Ascending  set.  1,  Superficial  branches  ;  two  or  three 
ascend  over  the  sterno-mastoid  to  the  integuments; 
ram.  superficial,  colli,  to  the  integuments  over  the 
ear  and  parotid  gland ;  a  filament  anastomoses  with 
the  seventh  pair.  2,  Deep  branches ;  three  or  four 
small  nerves  to  the  sterno-mastoid,  digastric,  sple- 
nius,  &c. 

Descending  set.  1,  Internal  branches;  a.  an  anas- 
tomosing branch,  to  join  the  descendens  noni;  b.  phrenic 
nerve;  composed  of  branches  of  the  second,  third, 
and  fourth  cervical  nerves ;  it  descends  diagonally 
across  the  ant.  scalenus,  enters  the  chest  between 
the  subclavian  artery  and  vein,  descends  between 
the  pericardium  and  pleura  accompanied  by  an  ar- 
tery, (the  left  nerve  winding  around  the  apex  of  the 
heart,)  to  the  diaphragm,  on  which  it  ramifies:  it 
communicates  with  the  last  cervical  ganglion.  2, 
External  branches:  a.  supra  clavicular ;  b.  supra  acro- 
mial;  and  c.  sternal,  to  the  integuments  covering 
those  bones;  external  respiratory  (Bell,)  one  of  the 
several  deeper-seated  descending  branches,  which 
,  descends  on  the  side  of  the  thorax  to  the  serratus 
magnus  muscle. 

Posterior  set.     a.  A  branch  to  anastomose  with  the 


204  BRACHIAL   PLEXUS. 

spinal  accessory;  b.  branches  to  the  trapezius,  le- 
yator  scapulae,  and  rhomboidei. 

BRACHIAL  PLEXUS:  composed  of  the  anterior 
branches  of  the  four  last  cervical  and  the  first  dorsal 
of  the  spinal  nerves ;  these  branches  descend  paral- 
lel with  each  other,  between  the  scaleni  muscles,  and 
only  constitute  a  plexus  in  the  middle  of  the  axilia 
behind  the  tendon  of  the  pectoralis  minor. 

Collateral  branches,  4,  a.  infra  clavicular,  branches 
to  the  subclavius,  levator  scapulae,  and  rhomboidei ; 

b.  supra  scapular  nerve,  passes  through  the  supra  sca- 
pular notch,  to  the  supra  and  infra  spinati  muscles ; 

c.  sub-scapular  nerves,  two  or  three  branches,  which 
sometimes  come  from  the  circumflex  to  the  sub-sca- 
pularis  m.     d.  thnracicse,  four  or  five  in  number,  de- 
scend behind  and  before  the  clavicle,  to  the  surface 
of  the  pectoral  muscles,  b 

Terminal  branches,  6  in  number. 

1.  Circumflex,  turns  backwards  under  thelower  edge 
of  the  sub-scapular  muscle,  and  winds  round  the  sur- 
gical neck  of  the  humerus  with  the  inferior  circum- 
flex art.,  to  terminate  in  the  deltoid;  it  supplies  the 
teres  major  et  minor,  latissimus  dorsi,  and  skin  over 
the  shoulder. 

2.  Internal  cutaneous,  descends  on  the  inner  side  of 
the  arm,  pierces  on  the  fascia  a  little  above  the  elbow, 
divides  into  filaments,  which  generally  accompany  the 
veins,  and  ramify  in  the  skin  nearly  as  far  as  the  wrist. 

3.  External  cutaneous,  (perforans  casserii,)  pierces 
the  coraco-brachialis  m.,  descends  on  the  outer  side  of 
the  arm,  pierces  the  fascia  a  little  above  the  elbow, 
descends  beneath  the  skin,  to  which  it  is  distributed 
by  separate  filaments  as  far  as  the  anterior  and  pos- 
terior part  of  the  carpus ;  it  also  supplies  the  mus- 
cles along  which  it  passes ;  hence  its  name. 

4.  Ulnar  nerve,  descends,  on  the  short  head  of  the 
triceps,  passes  between  the  internal  condyle  and  ole- 


MUSCULO-SPINAL   NERVE.  205 

cranon,  through  the  space  between  the  two  heads  of 
the  flexor  carpi  ulnaris,  soon  gains  the  inner  side  of 
the  ulnar  artery,  which  it  attends  to  the  hand :  it 
terminates  in,  a,  a  superficial  branch,  which  supplies 
the  two  sides  of  the  little,  and  the  ulnar  side  of  the 
ring  finger;  and,  b,  a  deep  branch,  which  forms  an 
arch  by  inclining  outwards,  beneath  the  flexor  ten- 
dons, so  as  to  supply  the  interossei,  and  terminate  in 
the  adductor  pollicis ;  c,  dorsalis  carpi  ulnaris,  turns 
over  the  ulna  beneath  the  flexor  ulnaris,  to  supply 
both  dorsal  edges  of  the  little,  and  the  ulnar  edge  of 
the  ring  finger. 

5.  Median  nerve,  (the  largest  branch, )  arises  by  two 
heads,  which  embrace  the  axillary  artery :  it  descends 
1st,  on  the  outer  side  of  the  brachial  artery,  along  the 
outer  edge  of  the  coraco-brachialis  muscle;   2d,  it 
crosses  the  artery  to  lie  on  its  inner  side,  resting  on 
thebrachialis  anticus;  3d,  it  passes  between  the  two 
heads  of  the  pronator  teres,  and  descends  between  the 
flexor  sublimis  and  the  flex,  profund.,  between  the 
tendons  of  which  two  muscles  it  enters  the  palm  of 
the  hand,  where  it  divides  into  five  digital  branches. 
a,  The  thretf-ftrst  correspond  to  the  two  edges  of  the 
thumb  and  radial  edge  of  the  fore  finger ;  b,  the  two 
last  supply  both  edges  of  the  index,  and  middle,  and 
the  radial  edge  of  the  ring  finger:  c,  interosseous  an- 
ticus; attends  the  anterior  interosseous  artery,  with 
which  it  is  lost  on  the  back  of  the  carpus ;  d,  palmar 
cutaneous,  to  the- skin  on  the  palm  of  the  hand. 

6.  Musculo  spiral:  runs  with  the  superior  profunda 
artery  in  the  spiral  groove  of  the  humerus,  and  lies 
with  that  vessel  between  the  brachialis  anticus  and 
supinator  longus,  where  it  divides  into  :  a,  r.  radialis, 
soon  gains  the  outer  side  of  the  radial  artery,  along 
which  it  descends  to  within  a  short  distance  of  the 
wrist ;  it  now  turns  over  the  outer  edge  of  the  radius, 
its  terminal  branches  supplying  the  two  dorsal  edges 
of  the  thumb,  index,  and  middle  fingers,  and  the  radial 

18 


206  INTERCOSTAL   NERVES. 

edge  of  the  ring.  (The  dorsal  and  palmar  edges  of 
the  little,  and  the  ulnar  edge  of  the  ring  finger,  are 
thus  supplied  by  the  ulnar  nerve;  the  dorsal  and 
palmar  edges  of  the  thumb  and  other  fingers,  with  the 
radial  edge  of  the  ring  finger,  by  the  median  and 
radial  branch  of  the  musculo  spiral,)  b,  ramus  pro- 
fundus  (post,  interosseous,)  pierces  the  supinator 
brevis,  descends  with  the  post,  interosseus  artery,  and 
supplies  the  two  layers  of  extensor  muscles.  Each 
principal  artery  of  the  arm  has  thus  its  attendant 
nerve. 

The  skin  of  the  upper  arm  is  supplied,  1,  by  branches 
from  the  three  upper  intercostals,  (cutaneous  of  Wris- 
bera,)  which  traverses  the  axilla;  and,  2,  by  branches 
from  the  circumflex  and  spiral  nerves. 

Anterior  branches  of  the  dorsal  Nerves* 
A,  INTERCOSTAL  NERVES,  12  in  no.,  extend  from 
the  first  dorsal  intervertebral  foramen  to  that  between 
the  last  dorsal  and  first  lumbar.  As  a  general  rule, 
they  gain  the  corresponding  intercostal  spaces,  where 
they  run  (below  the  art.,)  between  the  intercostal 
muscles,  and  divide,  about  midway  between  the  spine 
and  sternum,  into  external,  or  cutaneous  branches,  and 
proper  intercostal  branches  or  continuations  of  the 
nerve :  the  latter  pierce  the  thorax,  near  the  sternum, 
to  supply  the  inner  part  of  the  pectoral  muscles;  the 
former  having  pierced  the  chest  at  the  point  above- 
mentioned,  send  anterior  cutaneous  branches,  which 
run  a  regular  parallel  course,  and  post,  cutaneous 
branches,  which  run  over  the  ext.  surface  of  the  latis- 
simus  dorsi.  The  intercostal  nerves  communicate 
close  to  the  vertebrae  by  ascending  and  descending 
branches,  and  send  one  or  two  filaments  to  the  cor- 
responding sympathetic  ganglia. 

The  first  dorsal  nerve  belongs  to  the  brachial  plexus, 
and  sends  therefore  but  a  small  intercostal  branch. 
The  second  intercostal  is  very  tortuous  before  it 


INGUINO-CUTANEOUS    NERVE.  207 

reaches  the  space;  the  cutaneous  branches  of  the  se- 
cond and  third  are  the  cutaneous  of  Wrisberg.  The 
fourth,  fifth,  sixth,  and  seventh  dorsal  intercostals 
follow  the  general  rule ;  but  the  eighth,  ninth,  tenth, 
and  eleventh  nerves  traverse  the  costal  attachments 
of  the  diaphragm  to  terminate  on  the  abdomen,  by 
cutaneous  and  muscular  filaments,  which,  in  rami- 
fying on  the  abdominal  muscles,  precisely  follow  the 
above  rule.  The  twelfth  intercostal  sends  a  muscu- 
lar branch  to  the  abdominal  muscles  as  above,  but 
its  cutaneous  branch  is  large,  and  descends  nearly 
to  the  side  of  the  ilium;  it  also  sends  a  branch, 
which,  with  the  ant.  branches  of  the  four  first  lum- 
bar nerves,  constitute  the  lumbar  plexus. 

THE  LUMBAR  PLEXUS,  besides  the  above  nerves, 
receives  a  branch  from  the  last  lumbar,  to  make  up 
the  uninterrupted  chain  of  connection  which  includes 
all  the  spinal  nerves ;  it  is  situated  on  the  second, 
third, and  fourth  lumbar  transverse  processes, covered 
by,  or  even  partially  buried  in,  the  psoas  muscle. 

Collateral  branches,  4  in  No. 

1.  Sup.  abdominal  branch  (ilio-scrotal)  arises  from 
the  first  lumbar  nerve,  perforates  the  psoas,  crosses 
the  quadratus,  runs  round  the  abdomen  parallel  to  the 
last  dorsal  branch  (which  it  much  resembles,)  and  at 
the  iliac  crista  gets  between  the  trans,  and  int.  oblique 
m.,   where  it  divides  into   an  abdominal  and  pubic 
branch;  the  former  is  distributed  to  the  muscles  like 
the  last  dorsal;  the  latter,  sometimes  joined  by  the 
next  branch,  runs  along  the  cord  with  which  it  escapes 
to  terminate  in  the  skin  of  the  labia  or  scrotum. 

2.  Inf.  abdominal  branch  (ileo-scrotal  minor}  crosses 
the  quadratus  and  iliacus  m.,  running  parallel  to, 
but  below,  the  former,  which  it  sometimes  joins; 
when  it  does  not,   it  is  seen  as  a  second  branch, 
making  its  way  through  some  part  of  the  inguinal 
region,  to  the  same  parts  as  the  former. 

3.  Ing  uino- cutaneous  (external  cutaneous.)    Arises 


208     ANTERIOR  CRURAL  NERVES. 

from  the  second  and  third  lumbar  nerve,  traverses 
the  psoas,  crosses  the  iliacus  below  the  last  nerve, 
and  escapes  between  the  two  ant.  iliac  spinous  pro- 
cesses. Ram.  a,  anterior  or  femoral  pierces  the  fas- 
cia, sends  a  cutaneous  branch  to  the  ant.  and  outer 
parts  of  the  thigh  down  to  the  knee  ;  b,  posterior  to 
the  skin,  over  the  tensor  vaginae,  glutei,  &c. 

4.  Genito-crural  (external  pudic.)  Arises  from  the 
second  lumbar  nerve,  traverses  the  psoas  muscle, 
descends  on  its  ant.  surface,  with  the  ext.  iliac 
art.,  and  just  before  it  reaches  the  groin  divides  into 
two  branches,  a,  internal  or  scrotal  branch,  crosses 
the  artery,  enters  the  inner  ring,  runs  beneath  the 
cord,  and  terminates,  like  the  ilio-scrotal,  in  the  la- 
bia  or  scrotum;  b,  a  cutaneous  branch,  which  termi- 
nates on  the  ant.  and  inner  part  of  the  thigh. 

Terminal  Branches  2  in  No. 

1.  Obturator  ;  arises  from  the  third  and  fourth  lum- 
bar nerves,  runs  beneath  the  inner  margin  of  the  psoas 
m.  along  the  brim  of  the  pelvis,  escapes  with  the  ob- 
turator artery  through  the  obt.  foramen,  and  in  a 
space  between  the  obturator  ext.  and  pectineus  m. 
divides  into  an  anterior  branch,  which  goes  to  the 
add.  brevis  et  longus  and  gracilis,  and  a  posterior 
branch  to  the  obt.  ext.,  and.  brevis,  and  magnus. 

2.  Ant.  crural  nerves ;  arises  from  the  second,  third, 
and  fourth  lumbar  nerves,  descends  along  the  outer 
edge  of  the  psoas  m.,  between  it  and  the  iliacus  inter- 
nus, and  immediatelybelowPoupart's  ligament  divides 
into  1,  a  superficial  set  of  branches,  usually  two  in  no., 
which  supply  the  skin  on  the  fore  and  inner  part  of 
the  thigh,  as  far  as  the  knee;  2,  a  deep  set,  of  these, 
a  branch  (n.  saphenus  major)  runs  in  the  sheath  of  the 
femoral  vessels,  becomes  subcutaneous  just  below  the 
knee,  and  accompanies  the  int.  saphena  vein  to  ramify 
on  the  inner  part  of  the  dorsuin  of  the  foot,  thesaph. 
mm.  runs  along  the  sartorius.    Numerous  branches, 


GREAT    SCIATIC   NERVE.  209 

divided  into  external  and  internal,  supplies  the  mus- 
cles on  the  ant.  and  outer  part  of  the  thigh. 

SACRAL  PLEXUS,  the  communicating  branch  of  the 
last  lumbar,  and  the  ant.  branches  of  the  four  first 
sacral  nerves,  unite  into  a  large  flat  cord,  which  is 
situated  deeply  in  the  posterior  part  of  the  pelvis, 
on  the  pyriformis  muscle:  it  is  covered  by  the  int. 
iliac  artery,  and  (on  the  left  side)  by  the  rectus. 

Collateral  Branches,  4  in  No.. 

1.  Hs&morrhoidal,  lower  part  of  the  rectum,  sphinc- 
ter, and  mucous  membrane. 

2.  Vaginal,  uterine,  and  vesical  filaments,  to  those 
organs. 

8.  Pudic  nerve,  it  exactly  follows  the  course  of  the 
int.  pudic  artery ;  Ram.  a,  a  branch,  which  pierces 
the  great  sacro  sciatic  ligament,  and  winds  round 
the  tuber  ischii  to  be  distributed  by  branches  cor- 
responding to  the  inf.  hsemor.  and  superf.  perineal 
art.,  to  the  skin  about  the  perineum  and  scrotum; 
b,  ramus  dorsalis  penis,  to  the  skin  of  the  penis  in 
the  male,  clitoris  in  the  female. 

4.  Smaller  sciatic  nerve,  it  escapes  from  the  pelvis 
at  the  lower  edge  of  the  pyriformis  m.  Ram.  a, 
muscular,  distributed  in  all  directions  to  the  gluteus 
maximus;  b,  cutaneous,  to  the  skin  over  the  flexor 
muscles  as  far  as  the  knee,  by  distinct  post,  and  int. 
cutaneous  br. 

Terminal  Branch. 

Great  sciatic  nerve;  escapes  at  the  lower  border  of 
the  pyriformis  muscle,  and  descends  between  the 
tuber  ischii  and  great  trochanter  to  the  middle  of 
the  thigh,  where  it  terminates  in  two  branches,  the 
post,  tibial  and  peroneal  m. ;  it  rests  upon  the  ex- 
ternal rotator  and  adduct.  m.,  covered  by  the  glu- 
teus maximus  and  hamstring  muscles.  Ram.  a, 
branches  to  the  obturator  int.,  gemelli,  glutens  max., 
18* 


210          EXTERNAL  SAPHENUS  NERVE. 

ext.  rotator,  and  adductor  muscles ;  b,  a  posterior, 
middle,  and  external  cutaneous  branch. 

Peroneal  nerve  (external  terminal  branch,)  de- 
scends along  the  tendon  of  the  biceps  muscle,  winds 
round  the  neck  of  the  fibula,  between  that  tendon  and 
the  external  head  of  the  gastrocnemius,  where  it  is 
subcutaneous,  and  between  that  bone  and  peroneus 
longus  m.  it  divides  into  three  terminal  branches. 

1.  Two  recurrent  branches,  which  supply  the  upper 
part  of  the  extensor  muscles,  like  the  tibial  recur- 
rent artery. 

2.  Musculo-cutaneous,  descends  in  the  course  of  the 
peroneal  trunk,  in  the   substance   of  the  peroneus 
longus  m.,  pierces  the  fascia  some  way  above  the 
ankle-joint,  and  divides  into  two  branches,  one,  (in- 
ternal) ramifies,  by  two  digital  branches,  on  the  in- 
ner border  of  the  foot,  and  first  and  second  toes: 
the    other    (external,)  by  jneans    of  three    digital 
branches,  which  correspond  to  the  digital  spaces, 
ramifies  on  the  outer  border  of  the  foot,  and  dorsal 
surfaces  of  the  three  last  toes. 

3.  Ant.  tibial,  runs  beneath  the  upper  part  of  the 
common  extensor  m.  to  the  interosseous  ligament, 
descends  along  the  ant.  surface  of  the  corresponding 
artery,  runs  beneath  the  annular  ligament  of  the 
ankle,  in  the  sheath  of  the  ext.  prop,  pollicis,  and  di- 
vides into  a  branch,  (deep  digital,)  which  runs  under 
the  dorsal  artery  to  supply  the  adjoining  edges  of 
the  first  and  second  toes;  and  one,  which,  after  send- 
ing delicate  filaments  to  the  interosseous  spaces,  ter- 
minates in  the  extensor  brevis  digitorum  m. 

The  collateral  branches  of  the  peroneal  nerve,  are, 
1,  communicans  peronei,  which  arises  in  the  popliteal 
space,  pierces  the  fascia,  and  unites  with  the  commu- 
nicans tibice,  to  form  the  ext.  saphenus  nerve,  under 
which  name  it  descends  with  the  vein  to  the  outer  side 
of  the  ankle,  and  sometimes  to  the  outer  side  of  the 
foot;  its  branches  are  calcanian  and  malleolar;  "2,  a 


OLFACTORY   NERVE.  211 

cutaneous  branch  to  the  skin  over  the  outer  and  back 
part  of  the  fibula, 

Post,  tibial  nerve,  (intern,  terminal  branch,)  de- 
scends, as  the  popliteal  nerve  on  the  outer  back  par* 
of  the  pop.  vein,  and,  as  the  post,  tibial  nerve,  along 
the  back  part  of  that  artery,  to  the  internal  annular 
ligament,  under  which  they  are  both  included  in  one 
fibrous  sheath.  Collateral  branches. 

1,  Muscular;  2,  communicans  tibise,  unites  with  the 
communic.  peronei  as  before  described;  3,  branches 
to  the  gastrocnemii  and  soleus. 

The  terminal  branches  are,  1,  inter  nal plantar  nerve, 
(the  larger,)  enters  the  sole  of  the  foot,  close  to  the 
calcaneum  and  above  the  flexor  mus  cles,  and  gives  off 
four  digital  branches,  which  supply,  as  the  median 
nerve  did  in  the  hand,  both  edges  of  the  three  first 
toes,  and  the  inner  edge  of  the  fourth ;  2,  External 
plantar  nerve,  (smaller,)  runs  outwards  between  the 
flexor  accessorius  and  flexor  brevis;  it  gives  off,  a,  a 
deep  branch,  which  enters  the  sole  of  the  foot  to  sup- 
ply some  of  the  muscles ;  and  b,  three  branches,  one 
of  which  runs  to  the  outer  edge  of  the  foot,  the  other 
two  (digital)  supplying  both  the  edges  of  the  little 
toe,  and  the  outer  edge  of  the  fourth  toe.  A  small 
branch  also  anas,  with  the  last  digital  branch  of  the 
internal  plantar  n. 

The  fifth  and  sixth  sacral  nerves,  which  do  not 
enter  into  the  formation  of  the  sacral  plexus,  are  ex- 
tremely small ;  the  latter  is  merely  a  delicate  filament 
scarcely  observable.  The  fifth  anas,  above,  with  the 
fourth,  and,  below,  with  the  sixth;  the  latter  pierces 
the  sacro-sciatic  ligament  to  terminate  by  three  cu- 
taneous branches  upon  the  coccyx. 

CEREBRAL  NERVES,  9  PAIRS. 

1.  OLFACTORY,  Or.  by  numerous  filam.  from  the 
under  surface  of  the  olf.  lobes ;  term,  roof  of  the  nares 
septum  and  two  sup.  turbin.  bones.  The  lobes  are 


212          INFERIOR    MAXILLARY    NERVE. 

attached  to  the  brain  by  a  pedicle,  which  sends,  1,  a 
middle  gray  root  through  the  subs.  perf.  to  the  soft 
com.;  2,  an  ext.  long  root,  to  the  post,  edge  of  fiss. 
Sylvii:  3,  an  int.  short  root,  to  the  inner  part  of  the 
ant.  lobe. 

2.  OPTIC,  Or.  optic  commiss.  term,  retina.     To  form 
the  comm.,  1,  the  inner  fibres  of  the  opt.  fascic.meet 
transversely;  2,  the  mid.  fib.  decussate;  3,  the  outer 
fibres  proceed  without  decussating. 

3.  MOTORES  OCULI,  Or.  by  a  linear  series  of  stria?, 
from  the  adjoining  edges  of  the  fascic.  innom.  at  the 
ant.  edge  of  the  pons;  term,  in  the  orbit  by  1,  ram. 
super,   to   lev.    palp,  and    sup.   rectus;    2,   ram.  inf. 
(larger,)  to  rect.  inf.  et  int.  inf.  obliq., — radix  ext. 
to  ophth.  gang. 

4.  PATHETICI  (delicate  long.)  Or.  valve  of  Yieus- 
sens;   term,  sub,  obliq.  joined  to  the  opthal.  nerve. 

5.  TRIGEMINI, (spinal  nerve,  double)both  roots  are 
attached  to  the  side  of  the  pons;  traced,  the  sensy.  to 
post,   half  of  the  medulla  obi.;    the  motor  to   ant, 
pyram.  within  the  pons.     The  semilunar  sensy.  gang. 
?Gasserian,)  rests  on  the  petrous  bone,  and  gives  off, 
1,  ram.  opthalm.;  2,  rani.  sup.  max.;  3,  R,  inf.  max. 
OPHTHALMIC.  Ram.  a.  lacrymal;  1,  fil.  malar;  2,  'fil. 
palp.,  to  palp,  and  conjunc.;  3,  fil.  lacrymal,  to  the 
gland,  anas,  with  the  fascial  and  s.  max.  n.  b.  frontal; 
fil.  1,  supra  orbitar;  '2,supratrochlear.  c.  nasal;  l,long 
root  of  lent,  gang.  2,  fil.  infratrochlear.;  3,  ethm.  ant.; 
enters  the  skull,  and  descends  through  the  crib,  plate, 
sends  a  fil.  to  the  septum,  and  one  to  the  skin  of  ala 
nasi:   4,   two  fil.    ciliar.    SUP.    MAXILLARY,  ram.    a, 
orbitar,  1,  fil.  lacrymal,  2.  temp,  malar;  \),post.  dental, 
1,  fil.  post,  et  ant.,  to  post,  teeth,  gums,  and  bucci- 
nator; c,  ant.  dental,  antrum,  and  ant,  teeth;  d,  infra 
orbitar  (terminal.)     INF.  MAXILLARY,  joined  by  the 
motor  root  ram.  a,  muscular,  (motor  root,)  fils.  deep 
temp.,  masseteric,  buccal,  pterygoid;  b.  auricular, 
(superf.  temp.)  anas,  with  the  fascial;  c,  gustatory  or 


VAGUS    NERVE.  213 

lingual,  to  papil.  edge  and  tip  of  tongue,  anas,  with 
1,  chorda  tymp.,  2,  infra  dental;  d,  infra  dental,  fils., 
mylo-hyoicl,  mental. 

6.  ABDUCENTES,  Or.  ant.  pyramids  at  the  post,  edge 
of  the  pons ;  term.  ext.  rectus  m. ;  anas,  with  ophthal- 
mic n.  and  1st  cerv.  gang. 

~  (  AUDITORY,  portio  mollis,  \  attached.  Or.  fossa 
\  FACIAL,  portio  dura] between  the  corp. 
restif.  and  pons;  traced  the  former  round  the  c.  restif, 
to  the  strise  of  the  calamus  in  the  4th  vent.,  the  latter, 
through  those  bodies  to  the  stem.  PORTIO  MOLLIS  ; 
term,  by,  a,  ram.  to  the  cochlea,  b,  ram.  to  the  vesti- 
bule and  semicirc.  canals.  Anas,  with  port.  dura. 
PORTIO  DURA.  Ram.  In  the fal.  canal;  1,  receives 
the  Vidian,  2,  gives  off  chorda  tympani,  which  crosses 
the  tymp.  and  joins  the  gust,  nerve;  3,  receives  a 
filam,  through  the  bone,  from  the  vagus  (Arnold.) 
Out  of  the  ear.  Ram.  collateral;  1,  post,  auric,  2, 
styloid,  3,  submastoid.  Ram.  term.  ;  1,  cervico -facial 
r.  buccal,  mental,  cervical;  2,  temp,  facial;  anas, 
with  fifth  pair;  r.  temp,  orbitar,  and  infra  arbitar. 
j"  GLOSSO  PHARYNGEAL,  1  Or.  The  two  former 

8.  J  PNEUMOGASTRIC,  [-by  a  linear  series  of 

(  SPINAL  ACCESSORY,  )  fil.  from  the  corp.  res- 
tiform. ;  the  latter,  also  by  a  series  of  fil.,  from  the  lat. 
tract  of  the  cord,  extending  in  a  line  behind  the  lig. 
dentic.  from  the  vagus  to  the  fifth  cervical  nerve. 
The  three  escape  by  the  foramen  lacerum,  the  former 
in  a  fibr.  canal  distinct  from  that  of  the  two  latter. 
GLOSSO  PHARYNGEAL.  In  the  canal  it  presents  a  gan- 
glion, the  br.  of  which  are;  &,fil.  (Jacobson)  penet.  the 
inner  wall  of  the  tymp.  ,and  gives,  1,  fil.  to  the  carot. 
plexus,  2,  fil.  to  anas,  with  Vidian,  3,  fil.  to  the  otic. 
gang.  ;  b,  anas.  fil.  to  facial  nerve.  In  the  neck;  a, 
anas.jils.,  to  vagus,  and  spinal  access. ;  b,  r,  digast.  et 
stylo-hyoid;  c,  pharyngeal,  to  the  plexus;  d,  tonsil- 
lary ;  e.  Lingual  (term.,)  papil.,  and  muc.  mem.  at 
the  root  of  the  tongue.  VAGUS.  In  its  canal ;  a 


214  SYMPATHETIC    NERVE. 

ganglion,  ram.  a,  fil.  penet.  the  jugul.  foss.  to  anas, 
with  the  facial  in  its  acqueduct,  it  first  sends  a  fil.  to  r. 
Jacobson.  At  its  exit;  anas,  fil.,  to  spinal  access., 
hypoglossal,  pharyngeal,  and  sup.  cerv.  gang.  In 
the  neck;  a,  r. pharyn.  to  plexus;  b,  sup.  laryngeal, 
to  epiglottis,  crico-thyroid  muscle;  c,  r.  to  join  the 
cardiac  n.  In  the  thorax :  the  right  vagus  enters  be- 
tween the  subc.  art.  and  vein ;  the  left,  behind  the 
subc.  vein,  in  a  triang.  interv.  between  the  com.  carot. 
and  sub.  art.  Ram.  a,  n.  recurrens,  the  left  round  the 
aortic  arch,  the  right  round  sub.  art.;  1,  fils.  to  join 
the  cardiac  nerves  and  plexus,  2,  fil.  oesoph.,  and  tra- 
cheal,  3,  pharyngeal,  4,  term,  laryngeal  muscles,  and 
muc.  memb. ;  b,  ant.pulm.  brs.;  and  c,  post,  pulm.  brs. 
to  the  pulmon.  plexuses;  d,  cesophageal  plexus,  sur- 
round the  organ;  e,  gastric  plexus,  the  left  vagus  ant., 
the  right  poster.,  the  latter  joins  the  solar  plexus. 
SPINAL  ACCESSORY;  sometimes  forms  the  post,  root  of 
the  first  cerv.  pair.  In  the  canal,  it  is  joined  to  the 
vagus.  At  its  exit;  a,  anas.  fil.  to  glos. -pharyn., 
vagus,  and  three  upper  cerv.  nerves;  b,  r.  sterno 
mastoid,  which  m.  it  perf.  to  term,  in  the  trapezius. 
9.  HYPOGLOSSAL;  Or.  by  a  linear  series  of  fil.  like 
the  ant.  roots  of  the  spinal  nerves,  between  the  c.  oiiv. 
et  ant.  pyram. :  it  trav.  the  ant.  condyl.  for.  Ram. 
collat.;  a,  anas  fils.,  to  vagus,  sub.  cerv.  gang.,  first 
and  second  cerv.  nerves,  and  ling,  nerve  ;  Ram.  term.; 
a,  r.  to  the  glossal  muscles;  b,  r.  descend,  noni,  anas, 
with  cerv.  plexus,  and  sends  fil.  to  the  infra  hyoid 
muscles. 

SYMPATHETIC    SYSTEM. 

The  muscular  tissue  of  the  heart  and  digestive  canal, 
the  genital  and  urinary  passages,  the  arteries,  espe- 
cially those  of  the  trunk,  are  supplied  by  this  system; 
brs.  are  also  sent  to  the  organs  of  sense.  The  veins, 
lymphatic  vessels,  and  glands,  and  serous  membranes, 
receive  none  from  it.  The  system  consists  of,  1,  the 


SPLANCHNIC   NERVES.  215 

ganglia  of  the  sympathetic  ;  2,  detached  ganglia  in 
the  head,  chest,  and  abdomen;  3,  nervous  plexuses, 
derived  from  them.  The  ganglia,  although  they 
derive  their  energy  solely  from  the  cerebro-spinal 
system,  are,  to  a  certain  extent,  independent  sources 
of  nervous  power,  which,  by  means  of  their  plexuses, 
is  developed  in  such  combinations  as  are  suited  to  the 
associated  functions  they  are  designed  to  regulate. 
The  SYMPATHETIC  NERVE  consists  of  three  cervical, 
twelve  dorsal,  four  lumbar,  and  four  sacral  ganglia, 
extending  in  a  chain  from  the  first  cerv.  to  the  last 
sac.  vert,  and  connected  by  a  nervous  cord.  They 
commun.  by  1,  Ext.  br.,  one  in  the  cervical,  two  in 
the  other  regions  with  the  several  spinal  pairs ;  2, 
by  Ascend,  and  Descend,  br.  with  the  gang,  next 
above  and  below;  3,  they  send  Intern,  br.  principally 
to  attend  the  arteries;  and  4,  a  Visceral,  or  splanchnic 
set.  ARTERIAL  BR.,  a,  Nervimolles;  from  the  first 
cerv.  gang.,  to  accomp.  the  ext.  carot.,  and  its  br. 
formingplexus, named  from  them,  as  thyroid,  lingual, 
meningeal,  &c.;  b,  Nerv.  vertebralis,  from  the  last 
cerv.  gang,  accomp.  the  vert.  art.  and  its  br.  (The 
int.  carot.  andbr.  are  supplied  by  the  cavern,  plexus;) 
c.  fil.  to  the  subt.  are.  and  its  prim.  br.  and  to  the 
brach.  plex.;  d,  Aortic  fil.  from  the  dorsal  gang,  to 
accomp.  each  interc.  art.;  e,  Lumbar  Aortic  br  .The 
remaining  vessels  in  the  neck,  thorax  and  abdomen, 
are  attended  by  fil.  from  the  vagus,  cardiac  gang,  and 
semil.  gang.  VISCERAL.  FIL.  a,  Pharynaeal,  to  the 
plexus;  b,  Laryngeal,  joins  the  sup.  laryng.  n.;  c, 
Cardiac  nerves,  three  on  the  right,  sometimes  but  two 
on  the  left ;  arise  from  the  three  cerv.  ganglia,  and 
descend  in  the  thorax,  where  they  are  joined  by  card, 
br.  of  the  vagus  and  the  recur,  n.;  term,  in  the  card, 
gang,  and  plexus;  d,  Splanchnic  nerves,  two  in  number; 
the  sup. from  sixth, seventh, eighth, and  tenth  thoracic 
gang.;  the  inf.  from  the  eleventh  and  twelfth  gang. 
The  former  joins  the  semilunar  gang.,  the  latter-  the 


216  PULMONARY   PLEXUSES. 

renal  plexus ;  e,  splanchnic  br.  from  the  lumbar  gang, 
to  the  lumbar  aortic,  and  inf.  mesent.  plexus. 

CEREBRAL  GANGLIA,  a,  Lentic.  Gang.  sit.  between 
the  ext.  rectus  and  opt.  n.;  Post,  br.;  1,  fil.  or  long 
root,  from  the  nasal  n.;  2,  a  fil.  short  root,  from  inf. 
br.  of  the  third  pr.;  3,  fil.  to  the  caver,  plex.  Ant.  br.; 
sup.  and  inf.  ciliary  fil.  (two  oil.  br.  come  from  the 
nasal.)  b,  Meeker s  Gang.;  sit.  pteryg.-max  fissure; 
Post.  br.  1,  Vidian  nerve;  Int.  br.  2;  naso-pal.  n.; 
Descending  br.  3,  post.  pal.  n.;  4.  fil.  to  carot.  plex.: 
5,  fil.  to  super,  max.  n.  c,  Otic  Gang.  (Arnold;)  sit. 
inner  side  of  inf.  max.  n.  immediately  below  the  for. 
oval.  Ram.  1,  long  root,  which  is  the  middle  fil.  or 
Jacobson's  n.;  2,  short  root,  to  the  inf.  max.  n.;  3, 
fil.  to  lax.  tymp.  in. ;  4,  fil.  to  auric,  temp.  n. 

CARDIAC  GANG,  and  PLEXUS;  sit.  under  the  aortic 
arch,  and  between  it  and  the  trachea.  Comp.  cardiac 
nerves  and  card.  br.  of  the  vagus  and  recurrt. 
Ram.;  fil.  to  form  the  ant.  post,  coron.  plex. 

SEMILUNAR  GANG,  and  solar  plexus ;  sit.  on  the 
coeliac  axis:  the  ganglion  on  each  side  rec  the  grt. 
splan.  n.;  the  plexus  rec.  br.  from  the  sm.  splan.  n., 
and  right  vagus ;  sometimes  the  right  phrenic. 

The  br.  of  the  solar  plexus  accompany  the  neigh- 
bouring art.  and  branches,  forming  plexuses,  which 
are  named  from  them:  the  hepatic,  splenic,  and  gas- 
tric plex.,  commun.  with  the  vagus.  The  Sup.  mesen- 
teric  plex.  also  receives  post.  fil.  from  the  lumbar 
gang.  The  Renal  plex.  rec.  the  lesser  splanch.  nerves, 
and  forms  the  spermatic,  or  ovarian  plexus.  The 
Inf.  mesent,  plex.  rec.  fil.  from  the  lumbar  gang,  and 
the  hsemorr.  plex.  &c.  The  Hypogastric  plexus  is  sit. 
on  each  side  of  the  rectum;  it  is  comp.  of  lumbar 
and  sacral  fil.,  and  supplies  the  rectum,  bladder, 
uterus,  vagina  and  testicles. 

The  Pharyngeal  plexus  is  sit.  on  the  side  of  the 
pharynx  ;  it  is  comp.  of  fil.  from  the  vagus,  glosso-ph. 
and  sympathetic.  The  Pulmon.  plexus,  ant.  (smaller) 


SYMPATHETIC   NERVE.  217 

and  post,  (larger,)  are  comp.  principally  of  the  va- 
gus ;  it  rec.  br.  from  the  sympath.;  ram.  to  the  bron- 
chial tubes.  (Esophageal  plexus,  comp.  principally 
of  the  right  and  left  vagus. 

The  Sup.  cerv.  gang,  commun.  with  the  cereb. 
nerves;  1,  by  a  carot.  fil.,  which  forms  the  carot. 
plexus,  and  joins  the  cavernous  plexus;  it  receives 
a  fil.  from  the  Vidian  and  Jacobson's  n.,  and  sends 
fil.  to  the  sixth  pr.  of  n.  (The  cavern,  plex.  rec.  fil. 
from  the  third,  fifth,  and  sixth  prs.  and  Lent,  gang.; 
sends  fil.  along  the  br.  of  the  iiit.  carotid.)  2,  by  fil., 
which  commun.  at  the  base  of  the  skull,  with  the 
glosso-phar.  vagus,  hypoglossal,  and  facial  nerves. 
The  last  sacral  gang,  is  situated  on  the  front  of  the 
lower  extremity  of  the  sacrum  (impar.)  branches 
from  it  descend  to  the  anus. 

Although  the  sympathetic  nerve  is  here  described 
as  proceeding  from  the  spinal  nerves,  it  may  be 
more  proper  to  regard  it  as  a  distinct  nervous  sys- 
tem, which  communicates  by  filaments  with  the  spi- 
nal and  cerebral  nerves.  Its  filaments  preside  over 
the  functions  of  organic  life,  and  act  independently 
of  the  will. 


19 


218 


CHAPTER  IX. 

OF    THE    BONES,    LIGAMENTS,    AND    JOINTS. 

The  Bones  of  the  Head 

are  divided  into  those  of  the  cranium  and  face. 

The  cranial  bones  are  eight  in  number,  viz.,  one 
frontal,  two  parietal,  one  occipital,  two  temporal, 
one  sphenoid,  and  one  ethmoid. 

FRONTAL. — Sit.  upper  and  ant.  part  of  skull.  Ant. 
surface  convex,  is  slightly  depressed  on  the  mesial 
line,  indicating  the  union  of  the  two  pieces  of  which 
this  bone  consists  in  the  young  subject,  on  each 
side  of  this  bone  is  convex,  and  covered  superiorly 
by  the  scalp,  inferiorly  it  is  irregularly  concave,  and 
immediately  beneath  again  convex,  opposite  the 
frontal  sinus,  laterally  is  a  concavity  forming  part 
of  the  temporal  fosste,  bounded  above  by  the  tempo- 
ral ridge.  Post,  surface,  concave,  lodges  the  ant. 
lobes  of  the  brain ;  on  the  mesial  line  is  a  projecting 
spine,  which  divides  as  it  passes  upwards  into  two, 
leaving  a  depression:  the  former  gives  attachment 
to  the  falx  cerebri,  the  latter  lodges  the  commence- 
ment of  the  sup.  longitudinal  sinus. 

Inferior  surface  presents  the  orbital  plate,  this  is 
concave  beneath  and  forms  the  roof  of  the  orbit  in 
front,  and  to  the  outer  side  is  a  deep  depression  for 
the  lachrymal  gland,  and  internally  a  slight  depres- 
sion for  the  pulley  of  the  sup.  oblique  muse,  irregu- 
larly convex  above,  it  supports  the  ant.  lobes  of  the 
brain. 

The  circumference  of  the  frontal  bone  presents  a 
slight  projection  in  the  centre ;  from  this,  passing  out- 
wards, it  forms  the  coronal  suture  with  the  parietal 
bone ;  beneath  this,  it  articulates  with  the  ant.  inf. 
angle  of  the  parietal,  and  anteriorly  terminates  in  th« 


PARIETAL    BONE.  219 

ext.  angular  process  which  artic.  with  the  malar  bone, 
passing  inwards  from  this  are,  the  superciliary  arch, 
notched  near  its  inner  ext.  by  the  superciliary  notch, 
sometimes  a  foramen,  the  int.  angular  process  for  artic. 
with  the  os  nasi,  and  on  the  mesial  line  the  nasal 
xpine,  to  support  in  front  the  nasal  bones  and  poste- 
riorly artic.  with  the  nasal  lamella  of  the  ethmoid ; 
the  posterior  edge  of  the  orbital  plate  artic.  posteriorly 
with  the  lesser  wing  of  the  sphenoid,  internally  with 
the  orbital  plate  of  the  ethmoid,  and  more  anteriorly 
with  the  os  unguis.  The  foramina  are  nine,  viz., 
with  the  ethmoid  one  foramen  csecum,  and  four,  two, 
anterior,  and  two  posterior  int.  orbital ;  two  super- 
ciliary or  supra-orbital,  two  frontal  sinuses.  It 
articulates  with  four  bones  of  the  cranium ;  two 
parietal,  sphenoid,  and  ethmoid,  and  eight  bones  of 
the  face,  nasal,  sup.  maxil.  lachrymal,  and  malar. 
The  frontal  sinuses  exist  in  the  anterior  and  inner 
part,  and  extend  backwards  into  the  orbital  plates. 
PARIETAL. — Sit.  Superior  and  lateral  part  of  cra- 
nium. External  surface  convex,  presents  in  centre 
parietal  eminence ;  below  this  a  rough  surface,  a  little 
flattened  to  form  part  of  the  temporal  fossae  above, 
and  the  squamous  sutures  with  the  temporal  bone  be- 
neath. Inner  surface,  irregularly  concave,  is  marked 
by  the  convolutions  of  the  brain,  and  anteriorly  by 
the  branches  of  the  mid.  meningeal  art.  Circumference. 
The  upper  edge  forms  with  the  opposite  bone  the 
sagittal  suture,  it  is  grooved  internally  for  the  sup. 
longitudinal  sinus ;  the  anterior  forms  with  the  frontal 
the  coronal  suture;  the  posterior  joins  the  occipital 
to  form  the  lambdoid  suture;  the  inferior,  arched,  is 
overlapped  by  the  squamous  portion  of  the  tempv.  bone 
forming  the  squamous  suture.  The  ant.  inf.  angle, 
prolonged  downwards  to  artic.  with  the  sphenoid,  is 
grooved  internally  by  the  middle  art.  of  the  dura 
mater;  the  post.  inf.  angle  obtuse,  joins  the  mastoid 
part  of  the  temp.,  and  is  grooved  by  the  lateral  sinus. 


220  OCCIPITAL    BONE. 

The  parietal  artic.  with  five  bones,  frontal,  sphenoid, 
temporal,  occipital,  and  the  opposite  parietal. 

OCCIPITAL. — Sit.  post.  inf.  part  of  cranium.  Ext. 
and  post,  surface  irregularly  convex,  smooth  above,  is 
covered  by  the  scalp ;  it  is  separated  from  the  inferior 
portion  by  the  central  protuberance,  to  which  is  at- 
tached the  lig.  nuchae,  and  on  each  side  by  the  supe- 
rior transverse  ridge,  for  the  attachment  of  the  occi- 
pito-froiitalis  and  trapezius  muscle;  beneath  this, 
the  bone  forms  a  part  of  the  base  of  the  skull,  it  pre- 
sents a  rough  surface  for  the  insertion  of  the  com- 
plexus  and  splenius  capitis,  then  the  inferior  trans- 
verse ridge  and  another  rough  surface  for  the  inser- 
tion of  the  recti  postici  and  sup.  oblique;  on  the  me- 
sial line  is  a  rough  spine  for  the  attachment  of  the 
lig.  nuchae  ;  more  in  front  is  the  foramen  magnum,  oval 
in  shape;  it  transmits  the  spinal  marrow  and  its 
membranes,  vertebral  arteries,  and  spinal  accessory 
nerves  ;  in  front  of  this  is  the  basilar  process,  which 
passes  upwards  and  forwards,  and  joins  the  body  of 
the  sphenoid ;  its  superior  surface,  concave,  receives 
the  pons  Yarolii ;  the  inferior,  slightly  convex,  gives 
insertion  to  the  recti  cap.  antic,  muse,  posteriorly, 
and  anteriorly  forms  the  roof  of  the  pharynx.  On 
the  under  and  lateral  ant.  part  of  the  foramen  ni;i<r- 
num  are  the  condyle.s,  convex,  and  placed  obliquely 
to  artic.  with  the'atlas;  in  front  of  each  is  the  ant. 
condyloid  foramen,  for  the  exit  of  the  ninth  nerve  : 
and  behind,  the  post,  condyloid  foramen  for  entrance 
of  a  small  vein;  to  the  outer  side  is  i\\Q  jugular  pro- 
cess, bounding  the  foramen  lacerum  posticus,  and 
giving  insertion  to  the  rectus  cap.  lateralis. 

Internal  surface,  irregularly  concave,  is  divided  into 
four  fossae  by  a  crucial  ridge ;  the  superior  fossae  lodge 
the  post,  lobes  of  th£"cerebrum;  and  the  inferior,  the 
lateral  lobes  of  the  cerebellum ;  the  transverse  portion 
of  the  ridge  gives  attachment  to  thetentorium,  and  is 
grooved  for  the  lateral  sinuses ;  the  superior  portion 


TEMPORAL    BONE.  221 

of  the  vertical  ridge  gives  attachment  to  the  falx 
cerebri,  the  inf.  to  the  falx  cerebelli;  in  the  centre 
is  the  int.  occip.  protuberance  corresponding  to  the 
torcular  Herophili,  in  front  is  the  inner  opening  of 
the  foramen  magnum,  smooth  and  larger  than  the 
external. 

Circumference. — The  superior  pointed  extremity, 
n,nd  from  this,  outwards  to  a  projecting  spine,  articu- 
lates with  the  parietal,  forming  the  lambdoid  suture, 
in  front  of  this  it  joins  the  temporal,  and  still  more 
anteriorly  the  body  of  the  sphenoid.  This  bone 
artic.  with  six  bones — two  parietal,  two  temp., 
sphenoid  and  atlas.  Its  foramina  are  the  ant.  and 
post,  condyloid,  and  the  foramina  lacera  postica,  in 
basi  cranii ;  these  latter  are  completed  by  the  petrous 
bone,  and  transmit  the  int.  jug.  vein,  the  eighth  pair 
of  nerves,  and  some  small  meningeal  arteries. 

TEMPORAL. — Sit.  lateral,  middle,  and  inferior  part 
of  skull,  irregular  in  shape,  each  is  divided  into  three 
portions;  the  squamous, mastoid,  and  petrous.  The 
squamous  is  thin  and  overlaps  the  parietal.  Ext.  sur- 
face, convex  behind,  concave  in  front,  forms  part  of 
the  temp,  fossee,  from  near  its  interior  part  the  zygo- 
matic  process  runs  forwards,  and  terminates  in  a  su- 
ture, which  joins  the  malar,  to  complete  the  zygoma, 
this  presents  behind  its  roots  the  meatus  auditorius 
externus,  and  on  its  lower  margin  a  projection  for  the 
attachment  of  the  ext.  lat.  lig.  of  the  lower  jaw ;  in- 
ternal to  this  is  the  glcnoid  cavity,  divided  into  two 
by  theGlasserian  fissure,  which  transmits  the  chorda 
tympani,  and  the  tendon  of  the  levator  tympani;  be- 
hind the  fissure,  the  cavity  contains  a  portion  of  the 
parotid  gland;  in  front  is  the  articular  concave  sur- 
face for  the  condyle  of  the  lower  jaw,  in  front  of  this 
is  the  transverse  root  of  the  zygoma  convex  to  com- 
plete the  temporo-maxillary  artic. 

The  squamous  plate  is  marked  internally  by  the 
convolutions  of  the  brain  and  small  meningeal  vessels. 
19* 


222  TEMPORAL    BONE. 

The  mastoid  portion  occupies  the  post,  part  of  the 
temp. ;  ext.  surface  convex,  presents  the  mastoid  pro- 
cess for  the  insertion  of  the  sterno  and  trachelo-mas- 
toideus,  internally  it  is  grooved  by  the  lateral  sinus, 
its  interior  is  cellular.  Internal  to  the  mastoid  pro- 
cess, and  in  the  base  of  the  skull,  is  the  digastric 
groove  for  the  origin  of  the  digastric  muse. 

The  petrous  portion  runs  forwards  and  inwards  from 
the  preceding  portions;  triangular  in  shape,  its  base 
is  attached  to  them,  its  apex  is  free.  Inferior  surface, 
in  front  of  the  foramen  lacerum  posterius  is  the  aque- 
duct of  the  cochlea,  a  small  foramen  leading  into  the 
cochlea;  external  to  this  is  the  styloid  process  for 
the  attachment  of  the  styloid  muscles  and  ligaments: 
post,  and  ext.  to  this  is  the  stylo-mastoid  foramen  for 
the  exit  of  the  portio  dura;  in  front  and  int.  to  the 
styloid  process  is  theuiaro^V/  fontiucn,  leading  to  the 
carotid  canal,  and  in  front  of  this  is  a  rough  surface, 
to  which  are  attached  the  muscles  of  the  velum  and 
palate. 

Superior  surface,  irregular,  forms  part  of  the  mid- 
dle fossa  of  the  cranium  ;  in  front  is  a  groove  for  the 
Casserian  ganglion;  behind  this  a  slit-like  aperture, 
the  hiatus  Fallopii,  through  which  the  Vidian  nerve 
passes  to  the  aqueduct  of  Fallopius,  and  a  convex 
surface  formed  by  the  superior  semicircular  canal. 
This  surface  is  separated  from  the  posterior  by  a  thin 
edge,  grooved  by  the  sup.  petrous  sinus,  and  giving 
attachment  to  the  tent,  cerebelli.  Posterior  surface, 
nearly  flat,  presents  the  meatus  auditorius  internus, 
for  the  exit  of  the  seventh  pair  of  nerves  ;  behind 
this  is  a  slit-like  aperture,  which  leads  to  the  aque- 
duct of  the  vestibule..  The  petrous  bone  contains 
the  internal  ear. 

Circumference. — The  squamous  plate  articulates  in 
front  with  the  sphenoid;  above  it  overlaps  the  pa- 
rietal, and  thus  forms  the  squamous  suture  ;  behind 
this,  the  mastoid  portion  articulates  with  the  post.  inf. 
angle  of  the  parietal,  then  with  the  occipital;  in  front 


SPHENOID    BONE.  223 

of  this  the  petrous  bone  articulates  with  the  side  of  the 
basilar  process,  forming  the  foram.  lacer.  posterius, 
in  front  with  the  body  of  the  sphenoid,  forming  the 
foram.  lac.  anticus,  and  then  with  the  spine  of  this 
bone ;  the  temp,  articulates  with  five  bones,  the  parie- 
tal, sphenoid,  occipital,  malar,  and  inf.  maxillary. 

SPHENOID.  Sit.  In  the  centre,  base  and  lateral 
portions  of  the  skull.  It  is  divided  into  a  body, 
wings,  and  processes. 

The  body  is  in  the  centre,  from  it  anteriorly  pro- 
jects on  the  mesial  line  the  azygos  process  to  artic. 
with  the  nasal  lamella  of  the  ethmoid  above,  and  the 
vomer  beneath,  on  each  side  of  which  is  the  opening 
into  the  sphenoidal  sinus,  partially  closed  by  the 
bones  of  Berth),  on  its  superior  surface  is  the  Stella 
turcica,  a  deep  fossa  for  the  reception  of  the  pitui- 
tary gland,  bounded  in  front  by  the  ant.,  and  behind 
by  the  post,  clinoid  processes,  for  the  attachment  of 
the  edges  of  the  tentorium  cerebelli.  In  front  is  the 
olivary  process  for  the  lodgement  of  the  commissure  of 
the  optic  nerve,  behind  is  the  clivus  which  joins  the 
basilar  process.  At  each  side  of  the  olivary  process 
is  the  optic  foramen  for  the  exit  of  the  optic  nerve 
and  ophthalmic  art.;  and  still  more  exteriorly,  a 
thin  plate  of  bone,  the  lesser  wing  of  the  sphenoid,  or 
wing  of  Iiigrassius,  which  artic.  by  its  ant.  edge  with 
the  orbital  plate  of  the  frontal. 

The  great  iving  proceeds  from  the  side  of  the  body 
outwards,  forwards,  and  upwards,  its  anterior  surface 
forms  the  orbital  plate,  and  is  found  in  the  outer  wall 
of  the  orbit,  the  internal  concave  forms  part  of  the 
middle  fossa  of  the  cranium,  the  external  concave  is 
divided  into  two  by  a  crest,  the  superior  portion  forms 
part  of  the  temporal  fossa,  the  inferior  part  of  the 
zygomatic  fossa.  From  the  back  of  the  great  wing 
proceeds  the  spinous  process,  which  is  received  into  a 
retreating  angle  between  the  squamous  and  petrous 
bones;  in  it  is  the  spinous  foramen  for  the  passage  of 
the  mid.  art.  of  the  dura  mater,  and  from  it  descends 


224  ETHMOID    BONE. 

the  styloid  process,  to  which  is  attached  the  int.  lat. 
lig.  of  the  lower  jaw;  arit.  to  this  is  the  foramen  ovale 
for  the  exit  of  the  inf.  maxillary  nerve,  and  still 
more  anteriorly,  the  foramen  rotundum  for  the  exit  of 
the  sup.  maxillary  nerve.  Between  the  wings  is  the 
foramen  lacerum  orbitale,  sometimes  closed  exteriorly 
by  the  frontal,  which  transmits  the  third,  fourth, 
first  division  of  the  fifth  and  sixth  nerves,  some 
sympathetic  filaments,  one  head  of  the  ext.  rectus, 
and  the  ophthalmic  vein.  From  the  junction  be- 
tween the  body  and  great  wing  descends  the  ptery- 
goid process,  this  soon  divides  into  two  plates,  the  int. 
and  ext.  pterygoid,  separated  by  a  deep  fossa  pos- 
teriorly, but  united  anteriorly;  the  int.  plate  bounds 
the  posterior  nares,  on  its  outer  side,  and  terminates 
inferiorly  in  a  hook-like  process,  round  which  the 
tendon  of  the  tensor  palati  plays;  the  ext.  plate 
gives  attachment  on  its  outer  surface  to  the  ext. 
pterygoid  muscle,  and  on  its  innner  to  the  int. 
pterygoid;  at  its  root  is  the  fossa  navicularis  for  the 
origin  of  the  tensor  palati,  and  above  this  the  Vidian 
canal:  inferiorly  these  plates  leave  an  angle  into 
which  the  palate  bone  is  received. 

The  sphenoid  artic.  with  all  the  bones  of  the  cra- 
nium, and  five  of  the  face,  two  malar,  two  palate 
and  the  vomer.  The  processes  are  twenty-six,  four 
clinoid,  one  olivary,  one  ethmoidal,  four  wings,  two 
spongy,  or  bones  of  Bertin,  two  temporal,  two  orbi- 
tal, two  spinous,  two  styloid,  two  hamular,  and  four 
pterygoid.  The  foramina  are  fourteen  proper  and 
eight  common.  The  proper  are,  two  optic,  two  lace- 
rated orbitals,  two  round,  two  oval,  two  spinous,  two 
Vidian,  and  two  sinuses.  The  common  are  two  fora- 
mina lacera-antica,  two  spheno- maxillary  fissures, 
two  spheno-palatine  and  t  wo  posterior  palatine  canals. 

The  bones  of  Bertin  or  spongy  plates  of  the  sphenoid, 
are  two  triangular  plates,  which  assist  in  closing  up 
the  sphenoid  sinuses  in  front. 

ETHMOID.     Sit.  In  the  anterior  part  of  the  era- 


MALAR   BONE.  225 

nium,  between  the  orbits,  and  forming  the  roof  of  the 
nasal  cavities ;  of  a  cuboid  shape,  it  consists  of  a 
transverse  and  vertical  plate  and  two  lateral  masses ; 
superior  surface,  on  this  is  seen  the  transverse  or  cribri- 
form plate,  perforated  by  numerous  foramina  for  the 
exit  of  the  olfactory  nerves,  two  of  these  nearest  the 
centre  transmit  the  nasal  nerve;  in  the  centre  is  the 
crista  galli,  for  the  attachment  of  the  falx  cerebri; 
this  is  continued  downwards  forming  the  vertical  plate, 
the  lower  portion,  the  larger,, is  the  nasal  lamella;  it 
forms  part  of  the  septum  narium,  and  articulates  with 
the  nasal  spine  of  the  frontal,  nasal  bones,  triangular 
cartilage,  vomer  and  sphenoid  bone:  the  lateral 
masses  are  composed  of  delicate  cells  in  the  centre,  the 
spongy  bones  internally,  and  the  orbital  plates  exter- 
nally :  the  spongy  bones,  the  superior  and  middle,  are 
separated  by  the  superior  meatus;  of  the  cells,  the 
posterior  are  the  smaller,  and  open  into  the  superior 
meatus,  and  anterior  open  into  the  middle  meatus. 
The  orbital  plate  is  quadrilateral,  and  forms  part  of 
the  inner  wall  of  the  orbit,  its  upper  edge  artic.  with 
the  frontal,  and  here  forms  the  internal  orbital  fora- 
mina, the  lower  edge  artic.  with  the  sub.  maxillary 
and  palate,  in  front  with  the  os  unguis,  and  behind 
with  the  sphenoid.  The  ethmoid  artic.  with  two 
bones  of  the  cranium,  and  frontal  and  sphenoid,  and 
eleven  of  the  face,  the  nasal,  superior  maxillary  os 
unguis,  palate,  inferior  spongy,  and  vomer. 

The  principal  sutures  uniting  the  bones  of  the  head 
are  the  coronal,  sagittal,  lambdoidal,  squamous,  and 
addita  omcntum,  suiurse  lambdoidalis,  and  squamosse. 

THE  BONES  OF  THE  FACE 

are  fourteen  in  number — viz.,  two  malar,  two  sub. 
maxillary,  two  lachrymal,  two  nasal,  two  palatine, 
two  spongy,  one  vomer,  and  one  inferior  maxillary. 
MALAR.  Sit.  upper  and  outer  part  of  cheek.  Irre- 
gularly quadrilateral.  Ext.  surface,  convex,  presents 


226          SUPERIOR    MAXILLARY    BONE. 

a  few  small  holes  for  the  passage  of  vessels  and  nerves ; 
sup.  it  is  prolonged  upwards  to  join  the  frontal,  and 
form  the  outer  edge  of  the  orbit ;  internally  it  joins  the 
superior  maxillary ;  between  these  it  forms  part  of 
the  lower  margin  of  the  orbit;  behind,  the  malar  is 
concave,  and  forms  part  of  the  temporal  fossa,  and 
superiorly,  concave,  to  form  the  orbital  plate.  The 
lower  edge  of  the  malar  terminates  in  the  zygomatio 
process,  which  joins  that  from  the  temporal  to  form 
the  zygoma  ;  from  it  arises  the  masseter  muscle. 

SUPER.  MAXILLARY.  Sit.  central  part  of  the  face. 
Very  irregular;  it  is  composed  of  a  body  and  pro- 
cesses. The  body,  concave  anteriorly,  presents  the 
infra  orbital  foramen  ;  at.  the  upper  and  outer  part  of 
this  is  a  rough  surface  to  artic.  with  the  malar;  be- 
hind the  bone  is  convex,  and  articulates  with  the  pa- 
late; internally,  it  forms  the  outer*wall  of  the  nasal 
cavity,  and  here  presents  the  opening  into  the  an- 
trum,  nearly  closed  by  the  inf.  spongy  bone;  infe- 
riorly,  is  the  superior  alveolar  process,  and  the  palate 
process,  forming  the  floor  of  the  nose,  superiorly,  and 
the  roof  of  the  mouth  inferiorly.  This  terminates,  on 
the  mesial  line,  in  a  thin  plate,  to  receive  with  its 
fellow  the  lower  margin  of  the  vomer;  it  projects-in 
front  to  form  the  anterior  nasal  spine.  Superiorly  is 
the  orbital  plate  which  articulates  with  the  os  unguis 
and  ethmoid  internally,  the  palate  posteriorly,  and  the 
malar  externally  ;  behind  which  is  the  spheno-maxil- 
lary  fissure.  From  £he  inner  and  upper  part  of  this 
bone  the  nasal  process  runs  upwards  and  inwards  to 
join  the  frontal  bone;  its  anterior  edge  is  slightly 
grooved  to  receive  the  nasal  bone  and  alar  cartilage  ; 
the  post,  is  more  deeply  grooved  to  form  the  nasal 
canal;  its  internal  surface  forms  part  of  the  outer 
wall  of  the  nose,  and  has  attached  to  it  the  ant.  ext. 
of  the  inf.  spongy  bone.  The  body  is  hollowed  out  to 
form  the  sinus  or  antrum  Iliffhmorianum,  which  opens 
into  the  middle  meatus  narium. 


os  UNGUIS.  227 

PALATE.  Sit.  at  posterior  surface  of  the  sup.  max- 
illary, between  it  and  the  pterygoid  process  of  the 
sphenoid.  Irregular,  it  consists  of  a  horizontal  and 
vertical  plate.  The  horizontal  or  palate  process,  nearly 
square,  is  flat  and  rough  below  where  it  forms  the 
post,  part  of  the  palate,  smooth  and  concave  above  to 
form  the  floor  of  the  nose;  the  posterior  edge  is  thin, 
and  gives  attachment  to  the  velum ;  its  anterior  i» 
rough  and  articulates  with  the  superior  maxillary ; 
internally  it  artic.  with  its  fellow,  and  receives  in  a 
groove  thus  formed  the  vomer. 

The  vertical  plate  or  nasal  process,  ascends  from  the 
preceding,  and  terminates  superiorly  in  two  pro- 
cesses ;  the  ant.  or  orbital  process  forms  the  posterior 
angle  of  the  floor  of  the  orbit,  the  post,  artic.  with  the 
body  and  spongy  plate  of  the  sphenoid;  the  int.  sur- 
face is  concave,  and  forms  the  outer  wall  of  the  nasal 
cavity ;  it  is  divided  by  a  horizontal  ridge,  which  gives 
attachment  to  the  inf.  spongy  bone,  the  part  above 
forms  a  portion  of  the  middle  meatus,  that  below  of 
the  inf.  meatus.  The  anterior  edge  is  thin,  overlaps 
the  sup.  maxillary,  and  assists  in  closing  the  en- 
trance into  the  antrum;  the  post,  edge  joins  the 
pterygoid  process. 

The  tuberosih/,  or  pterygoid  process,  proceeds  back- 
wards from  the  lower  angle,  and  is  received  into  the 
interval  between  the  two  pterygoid  plates;  it  is  per- 
forated by  one  or  two  small  holes  which  lead  from  the 
palatine  canal.  Between  the  orbital  and  sphenoidal 
processes  is  a  fossa,  formed  into  the  spheno-palatim? 
foramen  by  the  sphenoid,  in  which  Meckel's  ganglion 
is  lodged. 

The  inferior  spongy  bone,  convex  internally,  concav« 
externally,  artic.  behind  with  the  palate,  in  front  with 
the  superior  maxillary ;  from  its  upper  margin  pro- 
ceeds upwards  a  process  which  joins  a  descending 
process  from  the  os  unguis  to  form  the  nasal  duct. 

The  os  unguis  is  placed  at  the  inner  and  fore  part  of 
the  orbit,  artic.  above  with  the  frontal,  below  with  the 


228  INFERIOR    MAXILLA. 

inf.  spongy  bone,  in  front  with  the  sup.  maxillary, 
and  behind  with  the  orbital  plate  of  the  ethmoid ;  it 
completes  the  ethmoid  cells  anteriorly. 

The  nasal  bones.  Sit.  beneath  the  nasal  process  of 
the  frontal.  Ant.  surface,  convex  above,  concave  be- 
low, is  perforated  by  one  or  two  small  holes  for  the 
escape  of  small  nerves.  Post,  surface  concave  and 
grooved  by  the  nasal  nerves.  Sup.  edye  thick,  artic. 
with  the  nasal  process  of  frontal  and  plate  of  ethmoid. 
Inf.  thin,  and  joins  the  alar  cartilages.  Int.  edge 
thick,  rests  against  its  fellow.  Ext.  groove  joins  the 
nasal  process  of  sup.  maxill.  The  nasal  process  of 
frontal  and  nasal  lamella  of  ethmoid  support  the 
nasal  bones  posteriorly. 

Vomer.  Sit.  in  the  lower  part  of  septum  narium. 
Sup.  margin  thick,  receives  the  azygos  process  of 
sphenoid.  Ant.  slightly  grooved,  receives  the  nasal 
lamina  of  ethmoid  posteriorly,  and  triang.  cartilage 
anteriorly.  Post,  separates  post,  nares.  Inf.  is  re- 
ceived in  the  grooved  between  sup.  maxillary  and 
palate  bones ;  the  sides  are  fiat,  and  covered  by  pi- 
tuitary mernb. 

INFERIOR  MAXILLARY  is  divided  into  body  and  rami. 
Body,  convex  in  front,  presents  on  mesial  line  the 
symphysis,  on  the  side  of  this  is  a  depression  for  the 
depressor  labii  muscles,  to  its  outer  side  the  mental 
foramen,  the  termination  of  the  inf.  dental  canal ; 
concave  posteriorly,  it  presents  on  the  mesial  line  a 
chain  of  projections;  to  the  superior  is  attached  the 
freenum  linguae,  to  the  middle  the  genio-hyo-glossi, 
and  to  the  inferior  the  genio-hyoid  muscle ;  on  each 
side  is  a  depression  for  the  sublingual  gland,  and 
beneath  a  depression  for  the  digastric. 

On  the  outer  surface  is  an  oblique  line  leading  to 
the  coronoid  process,  to  this  the  platysma  and  depres- 
sor anguli  mus.  are  attached  anteriorly,  the  buccina- 
tor posteriorly;  on  the  inner  side  is  a  similar  line  to 
which  the  mylo-hyoid  and  superior  constrictor  are 
attached;  beneath  this  is  a  groove  for  the  mylo- 


TEMPORO-MAXILLARY  ARTICULATION.  229 

hyoid  nerve,  and  beneath  this  a  depression  for  the 
Bubmaxillary  gland. 

The  rami.  pass  upwards  and  backwards  from  the 
body,  with  which  they  form  the  angle;  on  the  outer 
side  of  this  is  attached  the  masseter,  on  the  inner 
the  int.  pterygoid;  above  this  is  the  inferior  dental 
foramen  leading  to  the  inf.  dental  canal,  containing 
the  inf.  dental  vessels  and  nerves ;  its  lower  margin 
gives  attachment  to  the  int.  maxillary  lig. 

The  ramus  terminates  above  in  two  processes,  the 
coronoid&nd  condyloid,  separated  by  ihvsigmo id  notch. 
The  coronoid,  pointed,  gives  attachment  to  the  tem- 
poro-maxillary  articulation ;  it  is  oblong  transverse- 
ly, and  is  directed  backwards  and  inwards  ;  beneath 
it  is  the  nwk,  and  on  the  outer  side  a  tubercle  for 
the  attachment  of  the  ext.  lat.  lig. 

TEMPORO-MAXILLARY  ARTICULATION 

is  formed  by  the  condyle  of  the  lower  jaw  inferiorly, 
the  glenoid  cavity  and  transverse  foot  of  the  zygoma 
superiorly,  as  just  described. 

Ligaments.  Ext.  lat.  Or.  tubercle  on  outer  edge  of 
transverse  root  of  zygoma.  Ins.  outer  side  of  neck  of 
condyle.  Int.  lat.  Or.  spinous  process  of  sphenoid. 
Ins.  lower  part  of  circumference  of  inf.  dental  fora- 
men. Capsular.  Or.  Glasserian  fissure  and  circum- 
ference of  artlc.  Ins.  neck  of  condyle,  perforated 
internally  by  ext.  pterygoid  muscle.  In  the  interior 
of  the  joint  is  the  inter-aticular  cartilage,  correspond- 
ing to  the  artic.  surfaces  of  the  bones ;  the  ext.  ptery- 
goid is  attached  to  it  internally.  The  synovial 
memb.  is  double,  being  separated  by  the  int.  articu- 
lar cartilage. 

Inter -maxillary  lig.  thin  and  weak,  descends  from 
the  ext.  pterygoid  process  to  the  root  of  the  coro- 
noid process. 

Stylo-maxillary  lig.  Or.  styloid  process  of  tempo- 
poral  bone.    Ins.  inner  surface  of  angle  of  jaw. 
20 


230  VEBTFBRyE. 

THE  SPINE 

is  composed  of  twenty-four  vertebras,  united  by  fibro- 
cartilage  and  ligaments,  and  divided  into  seven  cer- 
vical,  twelve  dorsal,  and  five  lumbar.  Each  vertebra 
consists  of  a  body,  processes,  and  a  spinal  foramen. 

Cervical  vertebrse.  Characters — Body  small,  oval 
transversely,  concave  above,  convex  below,  anterior 
margin  projects  inferiorly.  Transverse  process  short 
and  bifid,  perforated  near  its  base  for  the  vertebral 
artery.  Articular  process  oblique;  superior  slightly 
convex,  directed  upwards  and  backwards;  inferior 
concave,  directed  forwards  and  downwards.  Spinous 
process  short,  horizontal,  and  bifid,  the  laminse  long 
and  narrow;  spinal  canaMarge  and  triangular. 

Peculiar  cerv.  vertebrse. — First  or  atlas,  no  body,  or 
spinous  process,  composed  of  two  half  arches,  ant. 
half  arch  convex  in  front,  concave  behind  artic.  with 
the  odontoid  process;  the  atlas  articulates  above 
with  the  condyles  of  the  occipital,  behind  which  is 
a  deep  groove  for  the  vertebral  art.;  below  with 
artic.  surfaces  on  the  dentata  or  axis.  Transverse 
process  single  and  projecting.  Second.  Odontoid 
process  for  artic.  with  preceding,  proceeds  from 
upper  surface. 

Seventh.  Spinous  process  long  and  projecting  pos- 
teriorly, and  not  bifid. 

Dorsal  vertebra.  Characters — Body  longer  than 
cervical,  heart-shaped,  long  axis  from  before  back- 
wards, flat  above  and  beneath.  On  the  sides  two 
half  artic.  surfaces  for  heads  of  ribs.  Transverse 
process  thrown  backwards,  and  marked  by  an  artic. 
surface  on  the  extremity  for  the  tubercle  of  the  rib. 
Articulating  process  directed,  the  superior  back> 
wards,  the  inferior  forwards.  Spinous  process  long 
and  drooping.  Spinal  ca?ial1  small  and  circular. 

Peculiar  dorsal  vertebrse.  First,  has  one  on  each  side 
a  distinct  facette  for  head  of  first  rib,  and  a  half  one 
for  that  of  second  rib,  resembles  cervical.  Tenth, 
eleventh,  and  twelfth,  one  facette  for  head  of  rib. 


INTERVERTEB&AL    LIGAMENTS.         231 

eleventh  and  twelfth  no  facette,  on  transverse  pro- 
cess for  tubercle  of  rib.  Twelfth,  inf.  artic.  process 
directed  outwards. 

Lumbar  vertebrse.  Largest,  oval,  long  axis  trans- 
verse, flat  above  and  below.  Transverse  processes 
long,  thin,  and  horizontal.  Artic.  processes.  Supe- 
rior, concave,  directed  inwards,  inferior  the  reverse. 
Spinous  processes,  short,  strong,  and  square,  project 
posteriorly.  Spinal  canal  large  and  triangular. 

Peculiar  lumbar  vertebra.  Last.  Transverse  pro- 
cess short,  inf.  artic.  process  directed  forwards. 
Body  cut  off  obliquely  to  articulate  with  sacrum. 

Ligament  of  Spine. 

Occipito-atlantoidean  artic.  Anterior  and  posterior 
lig.  Or.  from  edge  of  foramen  mag.  Ins.  upper  edge  of 
atlas.  Capsular  surrounds  artic.  surfaces.  Occipito- 
axoidean  lig.  Or.  anterior  and  inner  border  of  fora- 
men mag.  Ins.  posterior  surface  of  body  of  axis; 
passes  over  artic.  between  first  and  second  vertebrse. 

Artic.  between  atlas  and  odontoid  process. — Beneath 
preceding  are  the  transverse  and  oblique  or  check  liga- 
ments. Transverse,  Or.  a  tubercle  on  each  side  of  oblique 
process  of  atlas,  passes  across  the  back  of  odontoid 
process.  Ins.  opposite  side  of  atlas.  Check,  Or.  one 
on  each  side  from  near  summit  of  odontoid  process, 
passes  upwards  and  outwards.  Ins.  inner  edge  of 
foramen  magnum. 

Inter  vertebral  Ligaments. — Anterior  stretches  from 
the  front  of  the  body  of  the  second  vertebra,  along  the 
anterior  surface  of  the  spinal  column,  down  to  the  ex- 
tremity of  the  sacrum;  it  is  expanded,  and  is  attached 
most  firrrly  to  the  intervetebral  substance.  Poste- 
rior proceeds  from  the  back  part  of  the  body  of  second 
vertebra,  being  here  continuous  with  the  occipito  - 
axoidean  lig.  along  the  post,  surface  of  the  bodies  of 
the  vertebras,  and  is  implanted  inf eriorly  into  the  upper 
bone  of  the  sacrum;  its  edges  are  lunated  arid  well- 


232  THE    RIBS. 

defined ;  it  adheres  most  firmly  to  the  inter,  vert,  sub- 
stances, opposite  to  which  it  expands,  but  loosely  to 
the  bodies  of  the  vertebrae. 

Intervertebral  substance,  or  fibro- cartilage. — Between 
the  bodies  of  the  vertebrae  (except  first  and  second) 
to  which  it  firmly  adheres,  deeper  in  the  lumbar  than 
dorsal,  and  in  these  than  in  the  cervical  regions,  the 
fibres  run  obliquely,  so  as  to  decussate,  and  are  ar- 
ranged in  concentric  laminae  ;  about  the  centre,  but 
near  the  spinal  canal,  it  forms  a  semi-pulpy  substance, 
of  a  diamond  shape. 

Ligamenta  subftava  extend  in  pairs,  one  on  each 
side,  from  the  lamina  of  the  spinous  process  above  to 
that  below,  from  the  axis  to  the  sacrum,  so  as  to  close 
the  spinal  canal  between  the  laminae. 

Supra  spinous  lig.  extend  from  post,  tubercle  on 
the  occipital  bone  to  the  sacrum,  attached  to  the  ex- 
tremity of  each  spinous  process,  its  cervical  portion 
forms  the  lig  amentum  ?iuchss. 

Inter,  spinous  lig.  do  not  exist  in  the  neck,  are  thin 
and  weak  in  the  back,  but  are  strong  in  the  lumbar 
region  ;  the  fibres  stretch  from  one  spinous  process  to 
the  other. 

Inter,  transverse  lig. — A  few  irregular  fibres, 
stretching,  as  their  name  implies,  are  only  distinct  in 
the  lower  dorsal  and  lumbar  regions. 

The  Ribs, 

twenty-four  in  number,  are  divided  into  seven  true  and 
five  false.  The  former  are  connected  to  the  sternum 
by  means  of  the  costal  cartilages  ;  the  latter  are  only 
indirectly  connected  thereto. 

Each  rib  consists  of  a  head,neck,tubercle,and  body. 
Head,  slightly  expanded,  divides  into  two  concave 
facettes,  for  articulation  with  the  corresponding 
facettes  on  the  vertebrae,  separated  by  a  ridge  which 
gives  attachment  to  the  inter-articular  lig.  Neck  pro- 
ceeds outward  and  backwards,  slightly  rounded,  and 


THE   STERNUM.  233 

terminates  in  the  tubercle,  a  small  convex  facette, 
which  articulates  with  the  transverse  process  of  each 
vertebra,  beyond  which  it  is  rough  for  the  attachment 
of  the  posterior  costo-transverse  lig.  Body,  curved, 
convex  outwards,  concave  internally,  presents  pos- 
teriorly an  oblique  line  indicating  the  angle,  of  the 
rib,  at  which  point  the  bone  turns  forward.  The 
ridge  affords  attachment  to  the  sacro-lumbalis  ten- 
dons, the  rest  of  the  body  is  covered  externally  by 
muscles,  internally  it  is  lined  by  the  pleura;  its 
upper  edge  is  thick  and  rounded,  its  lower  edge 
slightly  grooved  for  the  intercostal  vessels;  both  give 
attachment*to  the  intercost.  muscles.  Ant.  extremity, 
slightly  expanded,  is  concave,  and  receives  the  ex- 
tremity of  the  costal  cartilage. 

The^rs^  rib  is  short  and  flat,  and  has  no  angle ;  its 
upper  surface  is  marked  by  two  grooves  for  the  sub- 
clavian  vein  and  artery,  separated  by  &  ridge  for  the 
insertion  of  the  scalenus  antlcus  muse.:  the  head 
has  but  one  articulating  surface  for  the  first  verte- 
bra. The  tenth,  eleventh,  and  twelfth  ribs  have  but 
one  artic.  surface  on  their  heads ;  the  eleventh  and 
twelfth  have  neither  angle  nor  tubercle;  they  are 
short  and  thin,  pointed  anteriorly,  and  loose,  hence 
called  floating  ribs. 

The  costal  cartilages,  twelve  in  number,  resemble 
the  ribs  to  which  they  are  attached ;  the  first  is 
short,  those  of  the  true  ribs  articulate  with  the  ster- 
num, those  of  the  false  are  joined  together,  and  to 
the  cart,  of  the  last  true  rib,  excepting  the  eleventh 
and  twelfth,  which  are  free. 

The  Sternum  is  situated  on  the  mesial  line  of  the 
thorax,  in  front  sloping  downwards  and  forwards. 
Its  anterior  surface,  irregularly  flat,  is  covered  by 
the  skin  and  aponeurosis ;  its  post,  surface,  slightly 
concave,  bounds  the  ant.  mediastinum  in  front.  The 
sternum  is  marked  laterally  by  a  deep  articular 
surface  above  for  the  clavicle,  and,  beneath  this,  by 
20* 


234    BONES  OF  UPPER  EXTREMITY. 

articular  surfaces,  concave,  for  the  cartilages  of  the 
true  ribs.  It  consists  of  two  pieces,  the  superior 
short  and  triangular,  the  inferior  long  and  quadrila- 
teral; to  the  lower  extremity  of  this  is  connected 
the  xiphoid  cartilage. 

Ligaments  of  the  Ribs. — Anterior  costo-vertebral, 
Btretches  from  the  ant.  surface  of  the  head  of  each  rib 
to  be  inserted  by  radiating  fibres  into  the  vertebra 
above  and  below,  and  the  intervening  intervertebral 
substance.  Inter- articular  runs  from  the  ridge  on  the 
head  of  each  riVto  the  adjoining  inter-vertebral  sub- 
stance. Posterior  costo-tramverse  lig.  Or.  extremity  of 
transverse  process.  Ins.  non-articular  portion  of 
tubercle.  Middle  costo-transverse  lig.  connects  the 
back  part  of  the  rib  to  the  front  of  the  corresponding 
transverse  process.  Inferior  costo-transverse,  wanting 
in  the  first  and  last  ribs,  arise  from  the  lower  border 
of  the  transverse  process,  and  is  inserted  into  the  crest 
on  the  upper  edge  of  the  rib  beneath.  The  costal 
cartilages  are  connected  to  the  sternum  by  irregular 
bands  of  fibres  on  the  ant.  and  post,  surface  of  this 
bone:  the  artlc.  is  lined  by  synovial  membrane. 

THE  BONES  OF  THE  UPPER  EXTREMITY 

consist  of  the  clavicle,  scapula,  humerus,  radius,  and 
ulna,  the  carpal  bones,  metacarpus,  and  phalanges. 

Clavicle,  extends  from  sternum,  upwards  and  back- 
wards, to  the  acromion  process,  curved  like  an  italic 
/,  its  ant.  and  post,  surfaces  are  convex  and  concave 
in  opposite  directions.  Sternal  end,  thick  and  trian- 
gular, artic.  with  the  sternum.  Body,  nearly  cylin- 
drical. Acromial  end,  flattened,  and  rests  on  the  edge 
of  the  acromion  process,  by  a  small  articulating  sur- 
face; its  ant.  surface  gives  attachment  to  the  pect. 
major  and  deltoid,  its  post,  to  the  sterno-mastoid 
and  trnpezius,  its  under  surface  to  the  subclavius. 

Ster no- clavicular  Ligaments. — Anterior  andj^os^n'or, 
stretch  from  the  inner  ext.  of  the  clavicle  to  the 


SCAPULA.  235 

sternum.  Inter-clavicular,  extends  from  one  clavicle 
to  the  other,  behind  and  a  little  above  the  sternum. 
In  the  interior  of  the  articulation  is  an  inter-articular 
cartilage,  lined  by  a  double  synovial  membrane. 

Costo- coracoid,  Or.  cartilage  of  first  rib  passes  up- 
wards and  outwards,  enclosing  subclavian  between 
two  layers.  Ins.  under  surface  of  clavicle  and  root 
of  coracoid  process. 

Acromio  clavicular  ligaments,  superior  and  inferior, 
stretch  from  one  bone  to  the  other. 

SCAPULA,  Sit.  upper,  lateral,  and  posterior  part  of 
thorax,  extending  from  second  to  seventh  rib.  Int. 
or  ant.  surface  concave  and  marked  by  several 
ridges,  forms  the  subscapular  fossa,  and  give  attach- 
ment to  the  subscap.  muscle.  Ext.  or  post,  surface  is 
divided  by  the  spine  into  the  supra  and  infra-spi- 
natus  fossae,  muscle ;  the  latter  convex,  gives  at- 
tachment to  the  infra-spinatus,  at  its  lower  edge  to 
the  teres  minor.  A  quadrilateral  flat  surface  over 
the  angle  gives  attachment  to  the  teres  major.  The 
spine  commences  from  the  posterior  border  near  its 
upper  third,  passes  upwards  and  forwards,  and  ter- 
minates in  a  quadrilateral  flat  process,  the  Acromion: 
to  its  upper  margin  is  attached  the  trapezius,  to  its 
lower  the  deltoid.  Superior  margin,  thin  and  short, 
is  notched  anteriorly  by  the  supra-scapular  notch, 
in  front  of  which  arises  the  coracoid  process,  which 
curves  forwards  and  gives  attachment  to  the  coraco- 
brachialis  and  short  head  of  biceps  in  front,  and  the 
pect.  minor  internally.  Posterior  margin,  or  base, 
slightly  curved,  gives  insertion  to  the  rhomboid 
muscles.  Anterior  margin,  thick,  gives  origin  to  the 
long  head  of  the  triceps  near  the  neck  of  the  bone. 
The  superior  posterior  angle  gives  insertion  to  the 
levator  anguli  scapulae;  the  anterior  forms  the 
glenoid  cavity,  supported  on  an  elongated  process, 
the  neck.  Glenoid  cavity,  oval,  long  axis  directed 


236  HUMERUS. 

vertically,  is  concave,  to  receive  the  head  of  the 
humerus. 

Ligaments  of  the  Scapula.  Sup.  Proper  Lig.  crosses 
the  supra  scapular  notch,  and  gives  origin  to  the 
omo-hyoid  muscle.  Spino-glenoid  stretches  from  the 
under-surface  of  the  spine  to  the  upper  and  posterior 
border  of  the  glenoid  cavity.  Coraco-acromial  arises 
broad  from  the  coracoid  process,  passes  upwards, 
and  is  inserted  narrow  into  the  acromion. 

HUMERUS,  OR  ARM-BONE. — Head,  rounded  and  con- 
vex, forms  little  more  than  half  a  sphere,  is  directed 
upwards  and  inwards,  and  joins  the  glenoid  cavity 
to  form  the  shoulder-joint:  it  is  supported  by  the 
anatomical  neck,  forming  a  deep  groove  for  the  at- 
tachment of  the  capsular  ligament:  beyond  this  are 
the  greater  and  lesser  tuberosities,  the  former,  the  ex- 
ternal, has  three  facettes  for  the  insertion  of  the 
supra-spinatus,  infra-spinatus,  and  teres  minor 
muscles.  The  latter,  the  internal,  gives  insertion  to 
the  subscapularis  muse.;  between  them  in  front  is 
the  bicipital  groove  through  which  the  long  tendon 
of  the  biceps  runs;  beneath^them  the  bone  contracts 
and  forms  the  surgical  neck.  Body,  or  shaft,  round 
above,  is  twisted  in  the  middle,  flat  and  triangular 
below,  its  posterior  surface  gives  origin  to  the 
second  and  third  head  of  the  triceps,  between  which 
is  a  groove  for  the  musculo-spiral  nerve ;  on  the  inner 
surface,  near  its  centre,  is  a  rough  surface  for  the 
insertion  of  the  coraco-brachialis,  and  on  its  outer 
a  triangular  rough  surface  for  the  insertion  of  the 
deltoid ;  the  anterior  surface  beneath  this  affords 
origin  to  the  brachialis  anticus  muscle. 

The  lower  extremity  of  the  humerus  is  flattened  and 
twisted  a  little  forwards.  From  within  outwards  are, 
the  int.  condyle,  projecting,  gives  origin  to  the  tendon 
of  the  pronators  and  flexors,  and  the  int.  lat.  ligament; 
the  epiirochlea,  a  projecting  eminence,  the  trochlea,  an 
articular  surface  for  the  greater  sigmoid  cavity  of  the 
ulna,  bounded  in  front  and  behind  by  the  ant.  and 


THE   ULNA.  237 

post,  humeral  fossse;  a  slight  projection,  a  rounded 
tsmall  head,  the  capitulum,  to  artic.  with  the  head  of 
he  radius,  the  ext.  condyle,  slightly  projecting  for 
*he  origin  of  the  ext.  Lit.  lig.  and  the  supinators  and 
extensors ;  from  each  condyle  a  ridge  of  bones  pass  es 
upwards  to  the  humerus,  and  affords  attachmentto 
the  intermuscular  septa  and  some  of  the  muscles  of 
the  fore-arm. 

THE    SHOULDER-JOINT 

is  formed  by  the  glenoid  cavity  and  head  of  the 
humerus  just  described. 

Ligaments,  Capsulars,  arises  from  neck  of  scapula, 
outside  brim  of  glenoid  cavity,  descends  expanding 
round  the  head  of  the  humerus,  and  is  inserted  into 
the  anatomical  neck;  strongest  inferiorly,  weak  su- 
periorly, it  is  perforated  in  front  by  the  long  head 
of  the  biceps,  internally  by  the  subscapularis  ten- 
don, and  above  by  the  supra-spinatus. 

Coraco-humeral,  or  accessory,  extends  obliquely 
downwards  and  outwards  from  the  coracoid  process 
to  the  ant.  part  of  the  great  tuberosity.  Glenoid  sur- 
rounds the  brim  of  the  glenoid  cavity  and  is  continu- 
ous with  the  tendon  of  the  biceps. 

BONES    OF    FORE-ARM. 

Ulna  forms  the  inner  bone.  Sup.  ext.  present 
greater  sigmoid  notch  to  artic.  with  the  trochlea  of  the 
humerus,  bounded  above  by  the  olecranon  process,  to 
which  the  tendon  of  the  triceps  is  attached,  in  front 
by  the  cor onoid process  for  the  insertion  of  the  bran- 
chialis  anticus;  on  its  outer  edge  is  the  lesser  sigmoid 
notch  for  artic.  with  the  side  of  the  head  of  the  ra- 
dius. Body,  triangular  is  divided  into  three  sur- 
faces by  three  lines,  affording  attachment  to  the 
muscles  and  intermuscular  septa.  Lower  ext.  first 
contracted,  then  expands  and  forms  a  rounded  ex- 
tremity, to  artic.  with  the  concavity  on  the  radius, 


238  ELBOW-JOINT. 

on  its  inner  part  is  the  styloid  process  to  which  the 
int.  lat.  lig.  of  the  wrist  is  attached. 

Radius  lies  on  the  outer  side  of  the  fore-arm ;  sup. 
ext.  forms  the  head,  on  which  is  a  cup-like  cavity  to 
artic.  with  the  capitulum  of  the  humerus;  on  its  side 
an  artic.  surface  for  the  lesser  sigmoid  notch  of  the 
ulna;  below  this  is  the  neck  and  at  its  lower  and 
inner  part  the  tubercle  into  which  the  tendon  of  the 
biceps  is  inserted.  Body,  is  divided  into  three  sur- 
faces, by  three  lines  for  the  attachment  of  muscles 
and  fascia,  its  ext.  surface  convex  presents  near  its 
centre  a  rough  surface  for  the  insertion  of  the  pro- 
nator  teres.  Inf.  ext.  expanded  and  quadrilateral 
presents  in  front  a  concavity  for  the  insertion  of  the 
pronator  quadratus,  posteriorly  it  is  marked  by  three 
grooves  for  the  passage  of  the  extensor  tendons,  the 
middle  groove  lodges  the  extensor  secundi  internodii 
pollicis  tendon;  the  second,  to  the  ulna  side  of  this, 
transmits  the  extensor  com.  and  indicator  tendons: 
the  third  to  the  radial  side  of  the  first  is  divided 
into  two  for  the  tendons  of  the  extensores  carpi  ra- 
dialis.  Along  the  ext.  border  is  another  groove  di- 
vided into  two  for  the  extens.  ossis  metacarpi  and 
primus  internodii  pollicis  tendons;  externally  is  the 
styloid  process,  to  which  the  ext.  lat.  lig.  of  the  wrist 
is  attached,  and  on  its  outer  surface  the  tendon  of 
the  sup.  longus;  internally  a  concave  surface  to 
artic.  with  the  ulna  inferiorly,  is  the  artic.  surface  for 
the  carpus  divided  partially  into  two  by  a  slight  ridge. 

THE  ELBOW-JOINT 

is  formed  by  the  lower  ext.  of  the  humerus  and  upper 
extremities  of  the  ulna  and  radius  as  just  described. 
Ligaments.  Anterior,  Or.  anterior  surface  of  humerua 
around  ant.  humeral  fossa,  descends  obliquely  in  front 
of  the  joint.  Ins.  annular  lig.  of  radius  and  coronoid 
process.  Post.  lig.  not  so  well  marked.  Or.  around 
post-humeral  fossa.  Ins.  ext.  of  olecranon  process. 
Int.  lat.  flat  and  triangular.  Or.  int.  condyle  of 


THE   CARPUS.  239 

humerus.  Ins.  side  of  the  olecranon  and  coronoid 
process.  Ext.  lateral,  Or.  ext.  condyle  of  humerus. 
Ins.  side  of  annular  lig.  of  radius. 

Superior  Radio-  Ulnar  Artie,  formed  by  the  side  of 
the  head  of  radius  and  lesser  sigmoid  cavity  of  ulna. 

Ligaments.  Annular  Or.  from  front  and  back  of 
lesser  sigmoid  cavity  of  ulna,  surrounds  the  edge  of 
the  head  of  the  radius.  Oblique  lig.  Or.  root  of  co- 
ronoid process,  descends  obliquely  outwards.  Ins. 
side  of  radius  below  its  tubercle. 

Inferior  Radio- Ulnar  Articulation,  formed  by  con- 
vex side  of  lower  ext.  of  ulna,  and  concavity  on  in- 
ner side  of  radius,  the  ligaments  are  anterior  and 
posterior,  composed  of  irregular  fibres  attached  to 
each  bone  close  to  artic.  surfaces. 

THE  CARPUS  consists  of  eight  bones  arranged  in 
two  rows. 

First  row,  from  without  inwards  as  follows,  sca- 
phoid, lunar,  cuneiform,  and  pisiform. 

Second  row,  trapezium,  trapezoid,  magnum,  and 
unciform. 

Scaphoid.  Largest  of  first  row,  convex  above,  con- 
cave beneath,  presents  four  artic.  surfaces,  superior 
to  artic.  with  the  radius,  internal  to  artic.  with  th<j 
lunar  above,  os  magnum  beneath,  inferior  double  to 
artic.  with  the  trapezium  and  trapezoides.  The  rest 
of  the  bone  is  rough  for  the  attachment  of  ligaments. 

Lunar  has  four  articulating  surfaces,  sup.  convex 
to  artic.  with  the  radius,  inf.  concave  to  artic.  with 
the  magnum  and  unciform ;  int.  flat  to  artic.  with 
the  cuneiform ;  ext.  flat  to  artic.  with  the  scaphoid. 

Cuneiform,  wedge-shaped,  the  base  is  directed  out- 
wards and  artic.  with  the  lunar;  apex  inwards,  con- 
vex and  smooth  artic.  with  the  fibro  or  inter-articular 
cartilage,  inf.  concave  to  artic.  with  the  unciform, 
ant.  flat  to  arctic,  with  the  pisiform. 

Pisiform,  pea-shaped,  artic.  with  but  one  bone,  the 
cuneiform. 


240  WRIST  JOINT. 

Trapezium,  concave  above  to  artic.  with  scaphoid, 
below,  convex  from  before  backwards,  concave  trans- 
versely to  artic.  with  the  metacarpal  bone  of  thumb, 
int.  artic.  with  the  trapezoid  and  inf.  with  the  second 
metacarp.  bone,  ant.  is  grooved  Jby  the  flexor  carpi 
radialis  tendon. 

Trapezoid,  smallest  of  this  row,  artic.  above  with 
the  scaphoid,  ext.  with  the  trapezium,  int.  the  mag- 
num inf.  with  the  second  metacarp.  bone. 

Magnum.  The  largest  of  the  carpal  bones,  sup. 
presents  a  convex  head  to  artic.  with  the  scaphoid 
and  lunar,  inf.  artic.  with  the  second,  third,  and 
fourth  metacarp.  bones,  ext.  with  the  trapezoid,  and 
int.  with  the  unciform,  its  post,  surface  is  large,  its 
ant.  thin  and  small. 

Unciform,  so  named  from  its  hook-like  processes, 
which  springs  from  its  ant.  surface,  above  its  artic. 
with  the  lunar,  below  with  the  fourth  and  fifth  meta- 
carp. bones,  ext.  with  the  magnum,  and  int.  with  the 
cuneiform.  The  free  surfaces  of  the  carpal  bone 
are  rough  for  the  attachment  of  irregular  bands  of 
fibres  connecting  them  together;  most  of  these  radi- 
ate from  the  ant.  surface  of  the  magnum. 

WRIST-JOINT  is  formed  by  the  lower  ext.  of  the 
radius  above,  the  scaphoid  and  lunar  beneath,  the 
ulna  is  separated  from  the  artic.  by  an  inter-articular 
cartilage. 

Ligaments.  Ext.  lateral.  Or.  styloid  process  of  ra- 
dius. Ins.  side  of  scaphoid, annular  lig.  and  trapezium. 
Int.  lat.  Or.  styloid  process  of  ulna.  Ins.  cuneiform 
and  pisiform  bones.  Ant.  &ndpost.  consist  of  irregular 
fibres  which  descend  from  the  radius  to  the  front  and 
back  of  the  first  row  of  carpal  bones.  The  anterior  and 
posterior  annular  ligaments  do  not  belong  to  this  artic.; 
they  have  been  described  (see  Fascix. )  In  the  interior 
of  this  joint  is  a  triangular  inter-articular  cartilage, 
between  the  ext.  of  the  ulna  and  cuneiform  bone,  its 
apex  is  attached  in  a  depression  on  the  outer  side  of 


PELVIS.  241 

the  root  of  the  styloid  process  of  the  ulna,  its  base  to 
the  right  separating  the  artic.  surfaces  on  the  radius. 
Like  the  larger  joints,  this  and  the  intercarpal  articu- 
lations are  lined  by  synovial  membrane. 

Metacarpal  bones,  five  in  number,  resemble  each 
other,  anteriorly  concave  and  H&YYOW,  posteriorly  broad 
and  convex,  sup.  ext.  irregular,  artic.  with  one  or  more 
of  the  carpal  bones,  inf.  ext.  presents  a  rounded  head, 
to  artic.  with  the  base  of  the  first  phalanx.  The 
first  metacarpal  bone  is  supported  by  one  bone,  the 
trapezium,  the  second  by  three,  trapezium,  trapezoid, 
and  magnum,  the  third,  by  one,  os  magnum,  the  fourth 
by  two,  os  magnum  and  unciform,  the^z/^Aby  one,  the 
unciform.  Small  artic.  surfaces  are  observed  on  the 
sides  of  the  four  inner  where  they  touch  each  other, 
or  one  of  the  carpal  bones ;  they  are  connected  by  ir- 
regular bands  of  fibres:  that  of  the  thumb  possesses 
lateral  ligaments. 

Metacarpo-phalangeal  articulations  are  provided 
with  lateral  ligaments  and  a  kind  of  capsular  lig. 

Phalanges. — Each  finger  possesses  three  phalanges, 
excepting  the  thumb,  which  has  but  two,  anteriorly 
concave,  posteriorly  convex,  the  metacarp.  ext.  of  the 
first  phalanx  is  concave,  to  artic.  with  the  head  of  the 
metacarp.  bone,  the  inf.  ext.  is  convex  from  before 
backwards,  and  concave  from  side  to  side  to  artic. 
with  the  second  phalanx,  which  presents  an  opposite 
arrangement.  The  last  articulation  resembles  this. 
The  ungual  phalanx  terminates  in  a  rough  pointed 
extremity.  These  articulations  possess  lateral  liga- 
ments and  a  kind  of  capsular  lig. 

THE  BONES  OF  THE  INFERIOR  EXTREMITIES 

Consist  of  the  pelvis,  femur,  tibia,  fibula,  tarsus,  me- 
tatarsus, and  phalanges. 

The  pelvis  is  properly  an  intermediate  structure 
between  the  trunk  and  lower  extremities.     It'is  com- 
21 


242  os  ILIUM. 

posed  of  four  bones,  the  sacrum  and  os  coccyx,  pos- 
teriorly, the  ossa  innominata  on  either  side. 

Os  sacrum  triangular,  the  base  above  the  apex  below. 
Sit.  between  ossa  innominata,  beneath  the  spine  and 
above  os  coccyx.  Ant.  surface  concave,  looks  down- 
ward and  forwards,  presents  four  transverse  lines  in- 
dicating the  pieces  of  which  it  originally  consisted, 
external  to  these  are  the  four  ant.  sacral  foramina 
through  which  the  sacral  nerves  pass  out,  between 
these  are  smooth  surfaces  from  which  the  pyriformia 
arises.  Post,  surface,  irregular  and  convex,  presents 
on  mesial  line  the  rudiments  of  spinous  processes, 
often  united  into  one  ridge,  beneath  which  is  a  trian- 
gular channel  in  which  the  spinal  canal  terminates, 
external  to  these  are  grooves  for  the  attachment  of 
muscles,  in  them  are  \\\Q  post,  sacral  foramina,  much 
smaller  than  the  anterior  of  the  exit  of  post,  sacral 
nerves,  external  to  these  is  a  row  of  small  tubercles 
analogous  to  the  transverse  processes  of  the  vertebrae. 
The  base  of  the  sacrum  turned  upwards  and  forwards 
presents  an  artic.  surface  for  the  last  lumbar  vertebrae, 
its  anterior  edge  forms  the  promontory,  behind  it  is  the 
opening  of  the  sacral  canal,  and  on  each  side  an  ob- 
lique artic.  process  concave,  and  looking  backwards 
and  inwards  to  form  the  artic.  process  of  the  last  lum- 
bar vertebrae.  The  apex  directed  forwards  and  down- 
wards articulates  with  the  first  bone  of  the  os  coccyx. 

Ext.  surface  presents  oblong  artic.  surface  to  join 
the  os  innominatum,  and  beneath  this,  a  smooth  mar- 
gin which  forms  part  of  the  great  sacro-sciatic  notch. 

Os  or  ossa  Coccygis — consists  usually  of  three  or  four 
irregular  small  bones,  articulated  with  each  other 
in  early  life,  but  consolidated  in  advanced  age. 

Os  innominatum,  irregular  in  shape,  forms  the  late- 
ral and  anterior  walls  of  the  pelvis ;  it  is  divided  into 
three  bones,  ilium,  ischium  and  pubes. 

Os  ilium  forms  the  largest  portion  of  the  os  inno- 
minatum ;  broad,  flat,  and  triangular,  its  base  is  at  its 


os  ISCHIUM.  243 

npper  part,  its  apex  at  the  acetabulum.  Ext.  surface, 
turned  also  a  little  backwards,  concave  in  front,  then 
convex,  and  again  concave,  it  presents  from  above 
downwards  a  rough  surface,  which  commences  a  short 
distance  behind  the  ant.  sup.  spinous  process,  passes 
Backwards  between  the  sup.  and  inf,  semicircular 
ridges,  expanding  considerably,  and  terminates  at  the 
post,  spinous  processes ;  this  gives  origin  to  the  glu- 
teus  medius  muscle,  a  rough  surface  at  the  back  part 
gives  origin  to  the  gluteus  maximus,  beneath  is  the 
inf.  semicircular  ridge,  from  which  and  the  surface 
beneath,  the  gluteus  minimus  arises;  beneath  this 
the  bone  projects  to  form  the  brim  of  the  acetabulum. 

Internal  surface  concave  forms  the  iliac  fossa  and 
lodges  the  iliacus  internus  muse. :  this  is  bounded  in- 
teriorly by  the  ilio-pectineal  line,  forming  the  boun- 
dary between  the  true  and  false  pelvis,  of  which  the 
os  ilium  forms  but  little.  This  line,  well  marked  an- 
teriorly, is  indistinct  posteriorly:  to  it  the  pelvic 
fascia  is  attached  through  its  greatest  portion,  and 
in  front  the  psoas  parvus  tendon  and  Gimbernaut's 
ligament. 

Os  ischium  forms  the  lower,  outer,  and  back  part  of 
the  pelvis.  Ant.  surface  turned  a  little  outwards, 
presents  externally  the  acetabulum,  a  deep  cup-like 
cavity  for  the  reception  of  the  head  of  the  femur, 
with  which  it  forms  the  hip-joint:  this  is  formed  two- 
fifths  and  a  little  more  by  the  ischium,  less  than  two- 
fifths  by  the  os  ilium,  and  one-fifth*by  the  pubes ;  it 
is  surrounded  by  the  brim,  well  marked  at  its  upper 
and  back  part,  shallow  elsewhere,  and  deficient  inter- 
nally, where  it  forms  a  notch  throughwhich  vessels  and 
nerves  pass  to  the  head  of  the  femur;  at  the  bottom, 
but  nearer  the  pubes,  is  an  irregular  depression  which 
affords  origin  to  the  round  lig.,  and  lodges  Haversian 
glands.  Beneath  this  is  a  groove  for  the  obturator 
ext.  tendon,  and  from  this  descends  a  rough  ridge 
which  gives  origin  to  the  quadratus  femoris  muse. ; 


244  SACRO   ILIAC    SYMPHYSIS. 

the  anterior  part  of  the  body  is  thin  and  presents  the 
obturator  foramen  inferiorly,  the  posterior  joins  the 
ilium,  and  forms  part  of  the  great  sciatic  notch,  be- 
neath is  the  tuberosity,  from  this  the  ascending  ramus 
ascends  to  join  the  descending  ramus  of  the  pubes. 

Ospubis  forms  the  inner  and  ant.  part  of  the  pelvis, 
from  the  preceding  the  ramus  ascends  to  terminate  in 
a  flat  surface  attached  to  its  fellow  at  the  symphysis, 
from  the  upper  extremity  of  this  the  horizontal  ramus 
passes  outwards  to  join  the  ilium ;  its  superior  margin 
is  the  crest,  between  which  and  the  symphysis  is  the 
angle.  A  sharp  ridge  separates  the  superior  surface 
of  the  crest  from  the  posterior,  this  is  the  commence- 
ment of  the  ilio-pectineal  line ;  in  front  of  this  the 
ramus  is  smooth  and  concave  and  supports  the  femo- 
ral vessels ;  at  its  inner  extremity  is  the  spine  or  tu- 
bercle, to  which  Poupart's  lig.  is  attached. 

The  circumference  of  the  os  innominatum  presents, 
first,  the  ant.  sup.  spinous process  of  the  ilium;  passing 
backwards,  it  forms  a  waving  surface,  the  crest  termi- 
nates behind  in  theposferior  superior  spine  of  the  ilium. 
A  little  below  this,  the  posterior  inf.  spine,  between 
these,  but  more  internal,  an  irregular  surface  to  form 
the  sacro-iliac  symphysis ;  passing  upwards  and  for- 
wards the  great  sciatic,  notch,  then  the  spine  of  the 
ischium,  to  which  the  lesser  sciatic  lig.  is  attached,  a 
groove  for  the  exit  of  the  obturator  internus  tendon, 
more  inferiorly  the  tuber  ischium,  then  the  ascending 
ramus  of  this  bone,  the  descending  ramus  of  the 
pubes,  symphysis,  horizontal  ramus,  anterior  infe- 
rior spine  of  the  ilium,  a  shallow  groove  for  the  exit 
of  the  inguino  cutaneous  nerve,  and  lastly,  the  an- 
terior superior  spine  of  the  ilium. 

Articulations  of  pelvis. — The  last  lumbar  vertebra 
is  joined  to  the  os  sacrum  by  the  inter-vertebral  sub- 
stance and  a  continuation  of  the  spinal  ligaments. 

Sacro-iliac  symphysis  or  synchondrosis,  between  the 
side  of  the  os  sacrum  and  inner  edge  of  os  innominatum 


FEMUR.  245 

the  bones  are  connected  by  anterior  and  posterior 
ligaments,  and  an  intervening  cartilage,  ossified  in 
the  old  subject. 

Great  sacro-sciatic  ligament  extends  from  the  side 
of  the  sacrum  and  coccyx  downwards,  forwards  and 
outwards,  to  be  inserted  into  the  tuber  ischii.  Lesser 
sacro-sciatic  lig.  lies  internal  to  the  preceding ;  smaller, 
arises  from  the  side  of  the  sacrum  and  os  coccyx, 
passes  outwards,  and  is  inserted,  pointed,  into  the 
spine  of  the  ischium.  The  great  sacro-sciatic  lig. 
converts  the  sciatic  notch  into  a  foramen,  the  lesser 
divides  this  into  two,  a  superior  larger,  an  inferior 
smaller,  through  the  former  pass  out  the  pyriformia 
muscle,  the  gluteal  art.  and  superior  gluteal  nerve, 
above  the  muse.;  the  greater  and  lesser  sciatic  nerves, 
sciatic  and  int.  pudic  art.  below  the  muse,  through 
the  lesser  sciatic  notch,  the  obturator  internus  tendon 
passes  out,  the  int,  pudic  art.  re-enter  the  pelvis. 

Obturator  ligament  nearly  closes  the  obt.  foramen, 
leaving  a  small  oblique  canal  at  its  upper  and  outer 
part  for  the  exit  of  the  obturator  art.  and  nerve. 
The  ossa  pubis  are  connected  by  an  intervening  fibro- 
cartilage,  an  ant.  and  posterior  and  a  sub.  pubic  liga- 
ment crossing  the  sub-pubic  angle. 

The  pelvis  is  divided  into  the  true  and  false  pelvis 
by  the  ilio  pectineal  line :  the  true  pelvis  lies  above 
this  line,  the  false  beneath  it. 

FEMUR,  or  thigh-bone,  is  the  only  bone  in  the  thigh  ; 
it  is  composed  of  a  head,  neck,  shaft,  and  inferior  ex- 
tremity. Head,  round  and  hemispherical,  presents 
near  its  centre,  but  a  little  below  it,  a  depression  into 
which  the  lig.  teres  is  inserted;  the  neck  proceeds 
from  this  downwards  and  outwards  and  j  oins  the  shaft 
at  an  acute  angle;  triangular,  its  base  joins  the  shaft, 
its  apex  the  head  of  the  bone,  its  surfaces  are  exca- 
vated, the  inferior  is  the  longest,  the  superior  the 
shortest;  the  posterior  is  longer  than  the  anterior;  it 
is  bounded  in  front  and  behind  by  the  ant. 
21* 


246  HIP-JOINT. 

inter -tro  chanter  ic  lines,  extending  from  one  trochanter 
to  the  other. 

The  shaft  is  twisted  and  curved,  convex  in  front, 
concave  posteriorly.  Sup.  ext.  on  this  are,  the  greater 
and  lesser  trochanters,  the  former  square,  convex  ex- 
ternally, forms  the  highest  part  of  the  shaft,  on  the 
inner  side,  near  its  root  is  a  pit  into  which  the  small 
rotators  outwards  are  attached;  the  latter,  pointed 
and  triangular,  lies  on  its  inner  and  posterior  part 
immediately  beneath  the  neck.  Post,  surface  pre- 
sents on  the  mesial  line  the  linea  aspera:  this  com- 
mences above  by  two  lines,  from  the  trochanters, 
and  terminates  inferiorly  in  two  lines  leading  to  the 
condyles,  it  gives  attachment  to  numerous  muscles, 
and  the  fascia  lata.  The  anterior  and  lateral  surfaces 
of  the  femur  are  alternately  concave  and  convex, 
and  are  covered  by  the  vasti  muscles.  Inf.  Ext.  ex- 
pands to  form  the  ext.  and  int.  condyles,  for  the  forma- 
tion of  the  knee-joint;  these  are  rounded,  oblong 
eminences,  the  long  axis  from  before  backwards,  and 
terminate  posteriorly  by  rounded  extremities,  they 
are  here  separated  by  a  deep  notch,  in  which  the 
popliteal  vessels  are  lodged  ;  in  front  they  are  par- 
tially separated  by  a  concave  artic.  surface  on  which 
the  patella  glides;  the  internal  projects  most  infe- 
riorly and  posteriorly,  the  external  is  wider  from 
side  to  side,  shorter  from  before  backwards,  and 
projects  most  interiorly.  They  are  incrusted  with 
cartilage  and  artic.  with  the  tibia  below  and  the  pa- 
tella in  front,  forming  the  knee-joint;  on  the  outer 
surface  of  each  is  a  projection  for  the  lat.  ligaments. 
Beneath  the  ext.  a  groove  for  the  popliteus  tendon. 

THE    HIP-JOINT 

is  formed  by  the  acetabulum  and  head  of  the  femur, 
as  just  described. 

Ligaments.  Capsular,  Or.  round  acetabulum  ext. 
to  the  cotyloid  ligament,  passes  downwards  and  out- 
wards around  the  head;  Ins.  neck  of  femur  anteriorly 


BONES   OF   LEG.  247 

as  far  as  ant.  inter-troehanteric  line,  posteriorly  into 
the  centre  of  the  neck  Strongest  superiorly,  and  pos- 
teriorly, where  it  receives  fibres  from  the  rectus  fe- 
moris,  and  anteriorly  where  it  is  strengthened  by  the 
accessory  lig.,  weakest  towards  the  obt.  foramen.  Ac- 
cessory lig.,  Or.  ant.  inf.  spine  of  ilium  passes  down- 
wards, inwards,  and  backwards.  Ins.  lesser  trochan- 
ter.  Cotyloid  lig.  surrounds  brim  of  acetabulum,  to 
which  it  is  attached  ;  it  passes  across  the  notch  in  its 
inner  part  and  terminates  in  two  extremities  attached 
to  its  opposite  edges.  Structure,  fibro  cartilaginous. 
Lig  amentum  teres,  Or.  bottom  of  rough  surface  in  ace- 
tabulum, passes  upwards  and  outwards,  contracting, 
and  is  Ins.  into  the  depression  on  the  head  of  the  fe- 
mur. Transverse.  Is  formed  by  some  fibres  of  the 
cotyloid  lig.  crossing  the  notch  in  the  acetabulum. 

Patella.  Sit.  in  front  of  knee-joint,  heart-shaped, 
the  base  above,  gives  insertion  to  the  rectus  tendon, 
its  apex  below,  gives  origin  to  the  lig.  patellae,  ante- 
rior surf  ace,  convex  and  rough,  is  covered  by  abursa, 
posterior,  covered  with  cartilage,  is  divided  into  two 
by  a  vertical  ridge,  of  which  the  ext.  concave  corre- 
sponds to  the  ext.  condyle,  the  int.  smaller  and  con- 
vex to  the  int.  condyle. 

BONES  OF  LEG.  The  leg  has  two  bones,  tibia  and 
fibula. 

Tibia,  extends  from  knee  to  ankle-joint.  Sup^  ext. 
expanded,  presents  two  condyles,  concave,  for  recep- 
tion of  the  condyles  of  the  femur,  to  which  they  cor- 
respond. They  are  separated  by  a  rough  surface  in 
front  and  behind,  also  by  the  spinous  process,  a  pro- 
jecting eminence.  On  each  side  of  the  head  of  the 
tibia  is  a  slight  prominence;  of  these  the  int.  is  best 
marked  for  the  attachment  of  the  int.  lat.  lig  ;  on  it 
is  a  groove  for  the  ant.  insertion  of  the  semimembra- 
nous  tendon  ;  on  the  under  and  back  part  of  the 
outer  is  a  convex  artic.  surface  which  joins  the  head 
of  the  fibula  ;  in  front  is  the  tuber osity  for  the  inser- 


248  KNEE-JOINT. 

tion  of  the  lig.  patellge.  Body  triangular,  large  above, 
contracts  and  becomes  rounded  below,  where  it  again 
expands  to  artic.  with  the  astragalus ;  it  is  divided 
into  three  surfaces  by  three  waving  lines,  of  these  the 
ant.  is  subcutaneous,  the  others  are  covered  by  mus- 
cles. Inf.  ext.  somewhat,  square,  presents  an  ant.  con- 
vex surface,  before  which  descend  the  extensor  ten- 
dons, a  post,  surface,  grooved  for  the  flexor  longus 
pollicis  tendon ;  externally  is  a  rough  surface  to  lodge 
the  lower  ext.  of  fibula,  smooth  below  to  artic.  with 
this  bone  ;  internally  is  a  square  projection,  the  inter- 
nal malleolus,  smooth  and  cartilaginous  externally,  to 
artic.  with  the  side  of  the  astragalus,  rough  and  con- 
vex internally  :  its  post,  edge  is  grooved  for  the  tibia- 
lis  posticus  and  flexor  communis  tendons.  The  low- 
er surface,  smooth  and  cartilaginous,  is  concave  to 
rest  on  the  upper  surface  of  the  astragalus. 

Fibula,  much  smaller  than  the  tibia.  Sit.  on  its 
outer  side,  and,  above,  a  little  posterior  to  it.  Sup. 
ext.  somewhat  rounded,  articulates  internally  with  the 
tibia:  rough  externally,  has  a  projecting  point  into 
which  the  ext.  lat.  lig.  and  tendon  of  biceps  are  in- 
serted ;  below  this  is  the  ntck.  Body,  presents  inter- 
nally a  sharp  ridge  which  divides  it  into  two  surfaces 
for  the  attachment  of  muscles  and  fascia.  Inf.  ext. 
larger  than  the  sup.,  terminates  in  a  triangular  ex- 
pansion, the  external  malleolus;  this  is  convex  inter- 
nally, and  covered  with  cartilage  to  artic.  with  the 
outer  side  of  the  astragalus,  rough  externally,  pointed 
inferiorly  for  the  attachment  of  the  ext.  lat.  ligaments, 
on  its  posterior  surface  is  a  deep  groove,  for  the  pe- 
ronseus  longus,  and  brevis  tendons. 

THE    KNEE-JOIXT 

is  formed  by  three  bones,  femur,  tibia,  and  patella,  as 
just  described.  Ligaments  divided  into  external  and 
internal.  External — Lig  amentum  patellse.  Or.  lower 
edge  of  patella,  passes  downwards  and  inwards.  Ins. 


SEMILUNAR   CARTILAGES.  249 

lower  part  of  tuberosity  of  tibia.  Int.  lateral  flat 
and  broad.  Or.  back  part  of  inner  condyle  of  fe- 
mur, descends  forwards.  Ins.  inner  condyle  of  tibia, 
passing  down  some  distance,  attached  closely  to  the 
int.  semilunar  cartilage.  Ext.  lateral,  round  and 
strong.  Or.  tubercle  on  outer  part  of  ext.  condyle 
of  femur,  descends  forwards.  Ins.  head  of  fibula. 
There  is  sometimes  a  second  ext.  lat.  smaller,  lying 
posterior  to  the  preceding.  Ligamentum  posticum.  Or. 
inner  condyle  of  tibia,  passes  upwards  and  outwards. 
Ins.  ext.  condyle  of  femur.  Some  consider  this  as 
one  of  the  insertions  of  the  semi-meinbranosus  mus- 
cle. 

Internal  ligaments.  Sit.  interior  of  joint.  Alar 
folds  of  the  sigmoid  membrane,  on  each  side  of  the 
patella.  Lie/amentum  mucosum.  Or.  fatty  substance 
behind  lig.  patella,  passes  upwards  and  backwards. 
Ins.  notch  between  condyle  of  femur.  Transverse 
passes  across  from  the  ant.  ext.  of  one  semilunar 
cartilage  to  that  of  the  other.  Crucial,  the  strongest 
of  the  internal  ligaments.  Anterior  or  external  Or. 
inner  and  post  part  of  ext.  condyle  of  femur,  de- 
scends forwards  and  inwards.  Ins.  in  front  of  spine 
of  tibia  and  int.  semilunar  cartilage.  Posterior  or 
internal.  Or.  outer  and  fore  part  of  inner  condyle 
of  femur,  descends  backwards  and  outwards.  Ins. 
behind  spine  of  tibia. 

Semilunar  cartilages  are  two  interarticular  fibro- 
cartilages,  which  rest  on  the  upper  artic.  surface  of 
the  tibia,  their  extremities  or  cornua,  pointed,  are  at- 
tached in  front  of  and  behind  spine  of  tibia;  thick 
and  convex  externally,  thin  and  concave  internally, 
the  upper  surface  concave,  the  under  nearly  flat;  the 
inner  is  the  more  fixed  by  the  attachments  of  the  int. 
lateral  and  ant.  crucical  ligaments,  the  ext.  is  grooved 
by  the  popliteus  tendon  and  inf.  ext.  artic.  artery.  The 
knee  is  lined  by  the  largest  synovial  memb.  of  the 
body,  passing  up  in  front  of  the  femur  behind  the 
rectus  tendon  to  an  extent  of  three  or  four  inches. 


250  BONES   OF    FOOT. 

Superior  tibio-ftbular  artic.  Ligaments.  Anterior  and 
posterior,  stretching  from  the  tibia  downwards  and 
outwards  to  the  head  of  the  fibula. 

Inferior  tibio-fibular  artic.  Ligaments.  Anterior  and 
posterior  similar  to,  but  much  stronger  than,  the  pre- 
ceding. Interosseous,  a  strong  band  of  fibres  lying 
between  the  bones,  and  connecting  them  firmly  to- 
gether. 

BONES  OF  FOOT. — Consist  of  the  tarsal  and  meta- 
tarsal  and  the  phalanges. 

Tarsal  bones  are  seven  in  number — viz.,  astragalus, 
calcis  or  calcaneum,  navicular,  cuboid,  and  three  cunei- 
form; they  may  be  arranged  in  two  rows,  an  anterior 
and  posterior,  or  an  internal  and  external;  the  poste- 
rior are  astragalus  and  calcis;  the  anterior,  navicu- 
lar, cuboid,  and  cuneiform ;  the  external  are  calcis 
and  cuboid;  the  internal,  astragalus,  navicular,  and 
cuneiform. 

Astragalus.  Sit.  upper,  inner  part,  and  nearly 
centre  of  tarsus;  irregular,  consists  of  body,  neck  and 
head.  Body,  quadrilateral,  presents  four  artic.  sur- 
faces ;  superior  square,  convex  from  before  backwards, 
concave  transversely  to  artic.  with  lower  ext.  of 
tibia,  continuous  internally  with  an  oblong  artic. 
surface  for  the  int.  malleolus  and  externally  with  a 
triang.  artic.  surface  for  the  ext.  malleolus.  Inf. 
surface  presents  two  artic.  surfaces  for  os  calcis, 
separated  by  a  deep  groove;  ext.  larger,  broad,  and 
concave;  int.  also  anterior,  and  convex;  the  groove 
affords  attachment  to  strong  interosscous  ligaments. 
Post,  surface  small  and  non-artic.  presents  a  deep 
groove  for  the  flexor  pollicis  longus  tendon.1  Ante- 
riorly is  the  neck  which  supports  the  head,  rounded, 
convex,  articulates  with  the  os  navicular  in  front, 
and  inferiorly  rests  on  calcaneo-navicular  lig. 

Os  calcis. — Largest  tarsal  bone.  Sit.  inferior,  back, 
outer,  and  part  of  inner  surface.  Superior  surface 
presents  two  artic  surfaces  for  the  preceding  infe- 


CUNEIFORM   BONES.  251 

rior,  to  which  they  correspond,  with  a  similar  deep 
groove  ;  internal  to  this  is  a  projecting  process,  the 
sustentaculum,  which  supports  the  astragalus,  and 
gives  attachment  to  the  calcaneo-cuboid  lig.  Inf.  sur- 
face, rough  and  excavated,  presents  posteriorly,  two 
tubercles,  the  internal  larger,  for  origin  of  muscles  and 
ligaments.  Int.  surface,  concave,  transmitting  ten- 
dons of  long  flexors  and  tibialis  posticus,  post,  tibial 
vessels  and  nerves.  Ext.  surface,  rather  flat,  presents 
a  tubercle  for  attachment  of  ext.  lat.  lig.  of  ankle,  and 
separates  grooves  for  the  peroneal  tendons.  Post, 
extremity,  convex,  projecting  behind,  presents  a  rough 
surface  inferiorly  for  the  insertion  of  the  tendo-Achil- 
lis,  above  which  it  is  smooth  for  a  bursa-mucosa.  Ant. 
Ext.  artic.  surface  for  os  cuboides. 

Navicular  or  Scaphoid. — Sit.  upper  int.  and  ant. 
part  of  tarsus,  oval,  with  long  axis  directed  down- 
wards and  inwards.  Post,  presents  concave  artic.  sur- 
face for  head  of  astragalus.  Ant.  three  artic,  surfaces, 
nearly  plane,  for  three  cuneiform  bones ;  its  cir- 
cumference is  rough  for  the  attachment  of  tendons 
and  ligaments.  A  tubercle  on  inner  and  lower  part 
gives  attachment  to  the  tibialis  posticus  tendon. 
Sometimes  its  outer  surface  articulates  with  the  cu- 
boid. 

Cuboid.  Sit.  upper,  outer,  and  ant.  part  of  tarsus. 
Post,  surface,  artic  with  os  calcis ;  ant.  with  fourth  and 
fifth  inetatarsal  bones  ;  sup.  surface,  flat  and  rough, 
for  attachment  of  ligaments ;  inf.  irregular  and  rough, 
is  grooved  by  aperoneuslongus  tendon.  Ext.  grooved 
for  peroneus  longus  tendon.  Int.  presents  two  artic. 
surfaces ;  posterior  for  scaphoid,  ant.  for  ext.  cunei- 
form. 

Cuneiform. — Three  in  number.  Sit.  int.  and  ant. 
part  of  tarsus.  Internal,  largest,  base  below,  apex 
above,  artic.  posteriorly  with  navicular ;  ant.  with 
first  metatarsal  bone ;  ext.  with  second  metatarsal 
and  mid.  cuneiform  ;  int.  presents  tubercle  for  inser- 
tion of  tibialis  an ticus  tendon  above,  and  the  posticus 


252  ANKLE-JOINT. 

beneath.  Middle,  smallest,  artic.  behind  with  the 
navicular,  before  with  the  second  metatarsal,  and 
laterally  with  the  preceding  and  ext.  cuneiform. 
External,  artic.  behind  with  navicular,  before  "with 
third  metatarsal  bone,  int.  with  middle  cuneiform 
and  second  metatarsal,  ext.  with  cuboid  and  fourth 
metatarsal  bone. 

Metatarsal  bones  are  five  in  number.  The  first  or 
internal,  the  shortest  but  strongest,  the  second  is  the 
largest,  they  are  all  convex  on  the  superior  or  dor- 
sal, concave  on  the  inferior  or  plantar  surface ;  late- 
ral surfaces  are  excavated  for  the  lodgment  of  inter- 
ossei  muscles.  First  is  supported  behind  by  the  ext. 
cuneiform,  its  ant.  ext.  round  and  large  artic.  with 
first  phalanx  of  great  toe,  grooved  interiorly  for  two 
sesamoid  bones,  and  here  gives  insertion  to  the  pe- 
roneous  longus  tendon.  Second  is  received  poste- 
riorly into  a  sulcus  formed  by  the  three  cuneiform 
bones.  Third  rests  post,  on  the  ext.  cuneiform. 
Fourth  and  fifth  on  the  os  cuboides,  their  ant.  extre- 
mities rounded  and  oblique,  artic.  with  the  first 
phalanges  of  the  toes. 

Phalanges  resemble  these  of  the  fingers,  except 
that  they  are  shorter  and  smaller. 

ANKLE-JOINT 

Is  formed  by  the  lower  extremites  of  the  tibia  and 
fibula  and  upper  surface  of  astragalus,  as  just  de- 
scribed. 

Ligaments.  Anterior  and  posterior  tiljio-tarsal  con- 
sist of  irregular  fibres  passing  from  the  tibia  down- 
wards to  the  astragalus  in  front  and  behind.  Int.  lat. 
lig.  triangular  and  flat.  Or.  lower  ext.  of  int.  mal- 
leolus  passes  downwards  radiating.  Ins.  inner  side 
of  calcis,  astragalus,  and  navicnlar  bone.  Ext.  lat. 
three  in  number.  Or.  inner  surface  of  ext.  malleo- 
lus  above  its  point,  the  anterior  passes  forwards,  and 
is  inserted  into  the  upper  and  outer  part  of  astraga- 
lus, the  middle  downwards,  backwards,  and  inwards 


LIGAMENTS   OF   FOOT.  253 

into  the  os  calcis,  the  posterior  backwards  and  in- 
wards into  the  back  part  of  the  astragalus. 

Ligaments  of  Foot. — The  only  important  are  the 
inf.  calcaneo-cuboid  and  inf.  calcaneo-navicular :  the 
former  stretches  from  under  surface  of  os  calcis, 
passes  forwards,  and  is  inserted  into  the  cuboid 
bone,  sheath  of  peroneal  tendon,  and  base  of  third 
and  fourth  metatarsal  bones ;  the  latter  arises  from 
sustentaculum  of  os  calcis,  passes  beneath  head  of 
astragalus,  and  is  inserted  into  under  part  of  the 
havicular  bone.  Irregular  bands  of  fibres  and  in- 
terosseous  ligaments  pass  between  parts  of  the  tar- 
sal  bones,  but  do  not  merit  particular  description. 
The  articulations  are  lined  by  synovial  membrane. 


22 


254 


CHAPTER  X. 

ORGANS    OF    SENSE. 

THE  organs  of  Sense  are  five  in  number — viz.,  the 
eye,  nose,  ear,  tongue,  and  skin. 


The  eye  is  the  organ  of  vision,  and  is  contained 
in  the  orbital  cavity. 

The  orbits,  or  orbital  cavities,  are  two  in  number. 
Each  orbit  forms  a  quadrangular  pyramid,  the  apex 
backwards  at  the  inner  ext.  of  the  foram.  lac.  orbi- 
tale,  the  base  forwards,  formed  by  its  circumferance. 
Its  four  sides  or  walls  are,  the  superior  or  roof,  the 
inferior  or  floor,  the  internal  and  external.  The  roof 
is  concave,  and  formed  by  the  orbital  plate  of  the 
frontal  and  lesser  wing  of  the  sphenoid ;  the  floor  is 
nearly  plane,  slopes  downwards  and  outwards,  and 
is  formed  principally  by  the  orbital  plate  of  the  su- 
perior maxillary,  a  little  anteriorly  by  the  malar, 
and  posteriorly  by  the  palate  bone ;  the  internal  wall, 
parallel  to  its  fellow,  is  formed  by  the  nasal  process 
of  superior  maxillary,  os  uiiguis,  os  planum  of  eth- 
moid, and  side  of  the  body  of  the  sphenoid;  the  ex- 
ternal wall,  the  shortest  thrown  outwards,  is  formed 
by  the  sphenoid  posteriorly,  the  malar  anteriorly. 
The  foramina  of  the  orbit  are,  the  optic,  foramen 
lacerum  orbitale,  spheno-maxillary,  and  the  anterior 
and  posterior  internal  orbital.  The  circumference 
is  formed  by  the  frontal  above,  the  malar  externally, 
the  malar  and  superior  maxillary  inferiorly,  and  by 
the  nasal  process  of  the  superior  maxillary  inter- 
nally. 

The  palpabrse,  or  eyelids,  cover  the  eye  in  front ;  the 
superior  is  the  larger  and  more  movable.  They  are 


LACHRYMAL    SAC.  255 

composed  of  skin,  orbicularis  palpebrarum,  carti- 
lage, fibrous  membrane,  glands,  mucous  membrane, 
and  fine  areolar  tissue. 

The  tarsal  cartilages  are  convex  anteriorly,  concave 
posteriorly,  one  margin  is  attached  by  fibrous  tissue, 
the  tarsal  ligaments,  to  the  circumference  of  the  or- 
bit; the  other  is  free,  and  contains  the  eyelashes; 
the  superior  is  broad  in  the  centre,  pointed  at  the 
extremities ;  the  inferior  forms  a  narrow  band. 

The  Meibomian  glands  or  follicles  lie  on  the  inner 
surface  of  each  tarsal  cartilage,  arranged  in  perpen- 
dicular rows,  and  open  on  the  free  margin  behind 
the  eyelashes. 

The  mucous  membrane  lines  the  interior  of  the  lids, 
and  is  a  continuation  of  the  conjunctiva,  which  is  re- 
flected over  the  anterior  surface  of  the  eyeball ;  at  the 
inner  canthus  it  forms  a  reddish  projection,  the  ca- 
runcula  lachrymalis,  and  a  fold,  the  plica  semilunaris. 

The  Lachrymal  apparatus  consists  of  the  lachrymal 
gland,  ducts,  puncta,  canals,  sac,  and  nasal  duct. 

The  Lachrymal  gland  is  lodged  in  a  deep  fossa  in 
the  upper  and  anterior  part  of  the  orbit;  convex 
above,  concave  inferiorly  ;  it  is  composed  of  a  num- 
ber of  granules  united  by  cellular  tissue. 

The  Lachrymal  ducts  proceed  from  the  gland,  are 
seven  in  number,  and  open  on  the  upper  and  outer 
surface  of  the  eye  by  perforating  the  conjunctiva. 

The  puncta  lachrymalia  are  the  small  orifices  of 
the  lachrymal  canals,  on  the  free  margin  of  each 
tarsal  cartilage  near  its  inner  extremity ;  the  canals 
proceed  from  these  in  a  curved  direction,  so  as  to 
form  an  elbow,  shape,  and  open  into  the  lachrymal 
sac  behind  the  tendo-oculi. 

The  lachrymal  sac  is  lodged  in  the  fossa  in  the  in- 
ner canthus,  and  is  crossed  a  little  above  its  centre 
by  the  tendo-oculi;  it  leads  into  the  nasal  duct ;  this 
descends  outwards  and  backwards,  and  opens  into 
the  inferior  meatus  narium. 


256  RETINA. 

The  eyeball,  or  globe  of  the  eye,  is  nearly  spheri- 
cal, the  prominence  of  the  cornea,  in  front  giving  to 
its  antero-posterior  axis  a  greater  length.  It  is  com- 
posed of  three  coats,  the  sclerotic,  choroid,  and  reti- 
na; of  three  humours,  the  aqueous,  lenticular,  and 
vitreous ;  and  three  membranes,  the  aqueous,  hyaloid, 
and  the  aris. 

The  sclerotic  coat  is  the  outer  fibrous  membrane, 
and  forms  the  posterior  four-fifths  of  the  eye;  it  is 
dense,  firm  and  resisting ;  its  fibres  interlace ;  it 
possesses  little  vascularity,  and  closely  resembles 
the  tunica  albuginea  testis.  It  is  deficient  anteriorly 
to  receive  the  cornea,  and  posteriorly  is  perforated 
by  the  optic  nerve,  forming  the  pars  cribrosa. 

The  choroid  is  the  vascular  coat  of  the  ey  e ;  it  lines 
the  interior  of  the  preceding,  from  which  it  is  sepa- 
rated by  the  principal  ciliary  vessels  and  nerves; 
its  inner  surface  covers  the  retina;  it  is  perforated 
posteriorly  by  the  optic  nerve,  and  anteriorly  is  at- 
tached to  the  sclerotic  by  the  ciliary  ligament,  and 
externally  forms  behind  the  iris  a  series  of  folds,  the 
ciliary  processes.  The  choroid  is  of  a  blackish  co- 
lour, from  the  presence  of  the  pigmenturn  nigrum, 
and  is  composed  of  two  coats,  an  external  venous 
(vasa  verticosa,)  and  an  internal  arterial  (membrana 
lluyschiana.) 

The  Retina  is  the  nervous  coat,  being  formed  by 
the  expansion  of  the  optic  nerve ;  it  lines  the  inte- 
rior of  the  preceding,  and  rests  by  its  inner  surface 
on  the  vitreous  humour;  anteriorly  it  terminates  in 
the  ciliary  ligament.  The  retina  consists  of  three 
coats,  an  external  cellular  or  serous  (membrana  Ja- 
cobi;)  a  central  nervous,  and  an  internal  vascular, 
formed  by  the  central  art.  of  the  retina.  Directly  in 
the  axis  of  vision,  that  is,  about  one  line  and  a  half 
external  to  the  entrance  of  the  optic  nerve,  the  re- 
tina presents  a  yellowish  spot,  the  yellow  spot  of  Seem-  ' 
mering.  It  disappears  soon  after  death. 


IRIS.  257 

The  Cornea  completes  the  globe  of  the  eye  in  front. 
Convex  anteriorly,  it  is  covered  by  the  conjunctiva; 
its  posterior  surface,  concave,  is  lined  by  the  mem- 
brane of  the  aqueous  humour ;  its  edges  are  bevelled 
off,  and  are  firmly  attached  to  the  margins  of  the 
opening  in  the  sclerotic  coat.  Its  structure  is  horny, 
and  is  composed  of  numerous  laminae,  united  by  fine 
areolar  tissue. 

The  Conjunctiva  gives  a  partial  covering  to  the 
eye,  the  anterior  portion  of  which  it  lines,  being  re- 
flected upon  it  from  the  inner  surface  of  the  lids. 

The  aqueous  humour  fills  the  anterior  chambers  of 
the  eye,  between  the  cornea  and  lens ;  it  is  a  trans- 
parent, thin  fluid,  and  is  secreted  by  the  serous 
membrane  lining  those  chambers,  hence  called  the 
membrane  of  the  aqueous  humour.  Of  the  chambers: 
these  are  separated  by  the  iris,  although  they  commu- 
nicate through  the  pupil;  the  anterior  is  the  larger. 

The  Lens  or  lenticular  humour,  forms  a  double  con- 
vex transparent  lens,  the  posterior  convexity  being 
the  greater;  it  is  enclosed  in  a  thin  membrane 
forming  its  capsule,  and  is  embedded  in  a  concavity 
in  the  forepart  of  the  vitreous  humour,  to  which  it 
is  attached  by  a  layer  of  the  hyaloid  membrane.  Its 
structure  is  composed  of  a  dense  humour,  arranged 
in  wedge-like  masses,  converging  towards  its  centre. 
Between  the  capsule  and  the  lens  is  generally  a.small 
quantity  of  fluid,  the  liquor  Morgagni. 

The  vitreous  humour  fills  the  posterior  three-fourths 
of  the  globe  of  the  eye,  and  supports  the  concave 
surface  of  the  retina;  it  is  intermediate  in  density 
between  the  aqueous  and  lenticular  humour,  and  is 
contained  in  cells  formed  by  its  investing  membrane, 
the  hyaloid  membrane.  It  is  traversed  by  a  branch 
of  the  central  art.  of  the  retina. 

The  Iris  is  the  thin  membranous  fold  which  sepa- 
rates the  chambers  of  the  eye;  it  is  perforated  near 
its  centre  to  form  an  opening,  the  pupil.  Its  external 
22* 


258  MUSCLES   OF   EYE. 

border  is  attached  to  the  ciliary  ligament,  its  inner 
forms  the  margin  of  the  pupil;  its  surfaces  are  lined 
by  the  membrane  of  the  aqueous  humour,  its  poste- 
rior is  blackened  by  the  pigmentum  nigrum,  and  is 
termed  the  uvea.  Its  structure  is  composed  almost 
wholly  of  blood-vessels  and  nerves :  some  have  as- 
signed to  it  muscular  fibres.  The  pupil  is  closed  in 
the  foetus,  up  to  the  seventh  or  eighth  month,  by  the 
membrana  pupillaris. 

The  ciliary  ligament  is  a  soft  whitish  annular  band 
formed  by  the  sclerotic,  choroid,  retina,  and  iris: 
from  its  internal  and  posterior  part  proceed  between 
sixty  and  seventy  triangular  folds  of  the  choroid 
membrane,  the  ciliary  processes. 

The  eye  is  supplied  with  blood  from  the  opthal- 
mic  artery ;  its  principal  branches  are  the  central 
art.  of  the  retina,  the  long,  short,  and  anterior  cili- 
ary arteries.  Its  nerves  are  the  optic  and  the  ciliary, 
derived  from  the  nasal  branch  of  the  ophthalmic  of 
the  fifth  and  the  lenticular  ganglion. 

The  muscles  of  the  globe  of  the  eye  are  the  supe- 
rior, inferior,  external,  and  internal  recti,  and  the 
superior  and  inferior  oblique.  The  recti  arise  from 
the  ligamentary  circle  surrounding  the  optic  fora- 
men and  nerve  (the  external  has  a  second  head  from 
the  side  of  the  sella  turcica,)  and  are  inserted  into  the 
sclerotic  coat  around,  and  about,  three  lines  distant 
from  the  cornea,  where  they  form  the  tunica  adnata, 
according  to  some  anatomists. 

The  superior  oblique  has  the  same  origin,  but  passes 
upwards,  forwards,  and  inwards,  through  a  pulley 
in  the  inner  and  upper  part  of  the  orbit,  winds 
backwards  and  outwards,  and  is  Ins.  into  the  outer 
and  back  part  of  the  globe  of  the  eye. 

The  inferior  oblique  arises  from  the  anterior  sur- 
face of  the  floor  of  the  orbit,  above  the  infra  orbital 
foramen ;  ascends  backwards  and  outwards,  and  is 
Ins.  into  the  external  and  posterior  part  of  the  globe 
of  the  eye,  near  that  of  the  superior  oblique. 


NASAL   CAVITIES.  259 

By  the  action  of  these  muscles  the  eye  is  turned  in 
every  direction ;  the  recti  also  turn  the  pupil  directly 
as  each  acts ;  the  oblique  rotate  the  eye,  so  as  to  turn 
the  pupil  in  opposite  directions. 

The  lev  ator  palp  ebrse  superior  is  belongs  to  the  upper 
lid.  Or.  in  common  with  recti  muse.  Ins.  upper  edge 
of  tarsal  cartilage.  Use,  to  raise  the  upper  lid. 

The  third  cerebral  nerve  supplies  all  the  muscles 
of  the  orbit,  except  the  superior  oblique,  which  is  sup- 
plied by  the  fourth,  and  the  ext.  rectus  by  the  sixth. 

THE  NOSE. 

The  nasal  cavities  are  two  in  number,  and  are 
nearly  symmetrical,  although  one  is  usually  larger 
than  the  other. 

Each  nasal  cavity  is  pyramidal  in  shape,  the  apex 
or  roof  is  arched,  and  is  formed  by  the  nasal,  frontal, 
cribriform  plate  of  ethmoid  and  body  of  sphenoid. 
The  base  or  floor  n.early  plane  is  formed  by  the  pa- 
late-plates of  sup.  maxillary  and  palate  bones,  the  in- 
ner wall  is  formed  by  the  septum,  composed  of  the 
vomer  and  triangular  cartilage ;  the  outer  wall,  irre- 
gular, slopes  downwards  and  outwards,  by  the  eth- 
moid, os  unguis,  sup.  maxillary,  inferior  spongy,  and 
palate  bones.  In  it  are  three  mcatuses  narium,  the 
superior  short  and  closed  anteriorly  is?  formed  be- 
tween the  superior  and  middle  spongy  bones,  the 
middle  meatus  between  the  middle  and  inferior  spongy 
bones,  the  inferior  meatus  between  the  inferior 
spongy  bone  and  floor ;  the  posterior  ethmoid  cells  and 
sphenoidal  sinus  open  into  the  superior  meatus;  the  an- 
terior ethmoid  cells  and  frontal  sinus  by  a  common 
opening,  and  the  antrum  by  a  distinct  aperture  open 
into  the  middle  meatus;  and  the  nasal  duct  into  the  in- 
ferior meatus.  The  posterior  nares  open  into  the  pha- 
rynx :  they  are  bounded  by  the  vomer  internally,  the 
int.pterygoid  plate  externally,the  sphenoid  above  and 
the  palate  plate  of  the  palate  bone  anteriorly. 

The  nasal  cavities  are  lined  by  a  nbro-mucous  mem- 


260  MEMBRANA   TYMPANI. 

brane,  the  pituitary  or  Schneiderian  membrane;  it  is 
supplied  with  blood  from  the  nasal  branches  of  the 
ophthalmic,  labial,  and  palatine  arteries.  Its  nerves 
are  the  olfactory,  the  nerve  of  the  special  sense  of 
smell  and  filaments  from  the  nasal  branch  of  the 
ophthalmic  and  naso-palatine  orMeckel's  ganglion. 
The  cartilages  of  the  nose  are  the  triangular,  which 
assists  in  forming  the  septum  narium,  the  lateral  na- 
sal, two  on  each  side,  superior  and  inferior,  which  form 
the  wings  or  sides  of  the  nose,  the  inferior  forms  the 
columna  or  ridge  between  the  anterior  nares. 

THE    EAR 

is  divided  into  the  external,  middle,  and  internal. 

The  external  ear  or  auricle  is  irregular  and  is  com- 
posed of  the  outer  border,  the  helix,  anterior  and  in- 
ferior to  which  is  a  semicircular  prominence,  the  anti- 
helix;  in  front  of  the  meatus  is  a  triangular  projec- 
tion, the  tragus,  opposite  to  which  is  the  anti-tragus. 
The  lower  pendulous  part  is  the  lobe.  The  depres- 
sions are  the  fossa  innominataand  the  concha.  The 
structure  of  the  external  ear  is  chiefly  fibro-cartilage, 
covered  by  skin  enclosing  a  few  muscular  fibres. 

Meatus  auditorius  externus  leads  from  the  concha  to 
the  membrana  tympani  which  separates  it  from  the 
middle  ear,  about  one  inch  or  an  inch  and  a  quarter 
in  length :  it  is  slightly  curved  convex  above ;  first 
runs  forwards  and  then  turns  a  little  backwards,  its 
lower  wall  is  longer  than  the  upper;  the  external 
half  of  the  meatus  is  formed  of  cartilage,  deficient 
anteriorly,  the  inner  is  bony.  It  is  lined  by  a  con- 
tinuation of  the  cuticle,  and  contains  numerous 
glands  which  secrete  cerumen  or  wax. 

The  middle  ear  or  tympanum  lies  between  the  mem- 
brana tympani  and  internal  ear. 

Membrana  tympani  is  a  thin  semi-transparent  mem- 
brane, nearly  circular,  slightly  concave  externally, 
convex  internally,  which  forms  a  septum  bet  ween  the 


VESTIBULE.  261 

external  and  middle  ear ;  to  its  inner  surface  is  at- 
tached the  handle  of  the  malleus.  Its  structure 
consists  of  a  central  fibrous  lamina,  lined  externally 
by  the  cuticle,  and  internally  by  mucous  membrane. 

The  Tympanum  forms  the  middle  ear,  it  is  a  small 
cavity  of  an  irregular  form ;  posteriorly,  it  communi- 
cates with  the  mastoid  cells,  anteriorly  it  leads  to 
the  Eustachian  tube,  externally  it  is  bounded  by  thfe 
membrana  tympani,  and  internally  by  the  vestibule. 
On  its  inner  wall  are  the  fenestra  ovalis,  or  vesti- 
buli ;  below  this,  the  promontory;  behind,  the  fenes- 
tra rotunda  or  cochleae ;  in  front,  the  canal  for  the 
tensor  tympani  muse. 

The  Eustachian  tube  is  a  narrow  canal  about  one 
inch  and  a  half  in  length,  which  runs  from  the  tym- 
panum downwards,  forwards,  and  inwards,  and 
opens  in  the  posterior  nares  opposite  the  the  inferior 
spongy  bone;  its  structure  is  fibre-cartilaginous. 

In  the  anterior  inferior  wall  of  the  tympanum  is 
the  inner  opening  of  the  Glasserian  fissure. 

The  tympanum  contains  four  small  bones,  the 
ossicula  auditus,  the  malleus,  or  hammer,  the  incus,  or 
anvil,  the  stapes,  or  stirrups,  and  the  os  orbicular e. 

The  internal  ear,  or  labryrinth,  is  composed  of  the 
cochlea,  semicircular  canals  and  vestibule. 

The  cochlea  forms  the  anterior  part  of  the  laby- 
rinth, of  a  conical  form,  its  apex  is  directed  down- 
wards, forwards,  and  outwards,  its  base  forms  the 
bottom  of  the  meatus  auditorius  internus. 

The  semicircular  canals  are  three  bony  tubes  in  the 
petrous  bone,  behind  the  vestibule,  with  which  they 
communicate  by  five  openings:  they  are  named  the 
superior,  posterior,  and  inferior  or  horizontal. 

The  Vestibule  forms  the  central  portion  of  the  la- 
byrinth; it  is  a  small  space  between  the  fenestra 
ovalis  and  meatus  auditorius  internus,  and  presents 
seven  large  foramina,  viz.  fenestra  ovalis,  fenestra 
rotunda,  and  the  five  orifices  of  the  semicircular  ca- 


262  EPIDERMIS. 

nals,  besides  smaller  openings  of  the  cribriform  plate 
and  the  aqueductus  vestibuli. 

The  portio  mollis  of  the  seventh  nerve  supplies 
the  internal  ear,  on  which  it  is  expanded,  as  the  re- 
tina is  in  the  interior  of  the  eye;  it  is  the  acoustic 
nerve.  The  tympanum  is  traversed  by  the  portio 
dura,  chorda  tympani,  and  some  smaller  nerves. 
(See  Nervous  System.) 

THE  TONGUE 

is  the  organ  of  taste:  its  situation  and  shape  need 
not  be  described.  Its  structure  consists  of  a  pecu- 
liar erectile  tissue,  supposed  by  some  to  contain  mus- 
cular fibres,  to  which  are  added  the  proper  lingual 
muscles  already  described ;  it  is  lined  throughout  its 
greatest  extent  by  mucous  membrane,  which  contains 
numerous  follicles,  glands,  and  papillae  scattered  over 
its  surface.  The  papillae  are  divided  into  three  classes 
the  calyciform,  fungiform,  and  conical,  or  filiform. 

The  calyciform  are  arranged  on  the  dorsum  of  the 
tongue,  near  its  base  is  a  V  shape ;  at  the  apex, 
which  is  turned  backwards,  is  the  foramen  csecum. 
The  fungiform  are  chiefly  towards  the  tip  and  sides. 
The  conical  or  filiform  occupy  the  greater  part  of  the 
dorsum. 

Tue  tongue  is  supplied  with  blood  by  the  lingual 
artery,  its  nerves  are  the  gustatory  and  lingual,  the 
former  being  the  nerve  of  special  sense,  the  latter 
that  of  motion. 

THE  SKIN 

is  the  organ  of  the  special  sense  of  touch,  as  well 
as  the  seat  of  peculiar  sensibility.  It  consists  of 
three  layers,  the  epidermis  or  cuticle,  rete  mucosum, 
and  durmis  or  cutis  vera. 

The  epidermis  or  cuticle  forms  the  external  layer ;  it 
is  composed  of  small  laminae  or  plates,  slightly  over- 
lapping and  connected  to  the  cutis  vera  by  numerous 


HAIRS   AND    NAILS.  263 

fine  filaments,  small  excretory  ducts  and  the  sheaths 
of  the  hairs. 

The  rete  mucosum,  although  described  as  a  distinct 
layer  of  membrane,  is  considered  by  some  to  be  gra- 
nules of  colouring  matter  deposited  in  the  interstices 
of  the  cells  of  the  cuticle  and  cutis,  so  as  to  give  to 
the  skin  its  various  colours  in  the  different  races. 

The  dermis  or  curtis  vara  is  composed  of  condensed 
areolar  tissue,  numerous  blood-vessels,  nerves,  and 
exhalent  vessels;  its  deep  surface  is  loose  and  irre- 
gular, and  is  connected  to  the  subjacent  parts  by  cel- 
lular tissues,  vessels,  &c.,  its  free  surface  is  provi- 
ded with  numerous  projections  forming  the  papillse, 
in  which  the  sense,  and  sensibility  of  the  skin  reside. 
The  dermis  contains  numerous  glands — viz.,  the  su- 
doriferous, or  sweat  glands,  the  sebaceous,  Meibo- 
mian,  ceruminosee,  &c. 

The  hairs  and  nails  are  appendages  of  the  skin, 
and  are  modifications  of  the  cuticle. 


14  DAY  USE 

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MAY  12 


